Autonomous remaining useful life estimation

ABSTRACT

The equipment comprises at least one computer and a material features acquisition system operable to detect a plurality of material features. The features are then evaluated according to rules that capture the multidiscipline knowledge of experts and are already inputted into the computer. The computer iterations are processed until an acceptable conclusion is made regarding the condition of the material under evaluation, thus alleviating the need for multidiscipline experts to examine and analyze all the material data manually.

RELATED APPLICATION

This application is a continuation in part of U.S. patent applicationSer. No. 10/867,004 having a filing date of Jun. 14, 2004 and acontinuation in part of U.S. patent application Ser. No. 10/995,692having a filing date of Nov. 22, 2004 (U.S. Pat. No. 7,155,369) and acontinuation in part of U.S. patent application Ser. No. 11/079,745having a filing date of Mar. 14, 2005 (U.S. Pat. No. 7,231,320) and acontinuation in part of U.S. patent application Ser. No. 11/743,550having a filing date of May 2, 2007 and a continuation in part of U.S.patent application Ser. No. 11/769,216 having a filing date of Jun. 27,2007.

TECHNICAL FIELD

This invention relates, generally, to non-destructive remaining usefullife estimation method and equipment, and more specifically, to provideautomatic and/or continuous non-destructive acquisition of materialfeatures, including evaluators and predictors of detected features, andautonomous evaluation capability of the material remaining useful life.

BACKGROUND OF THE INVENTION

As is known in the art, materials are selected for use based on criteriaincluding minimum strength requirements, useable life, and anticipatednormal wear. Safety factors are typically factored into the designconsiderations to supplement material selection in order to aid inreducing the risk of failures including catastrophic failure. Failuresoccur when the required application strengths exceed the actual materialstrength either due to the misapplication of the material or due tomaterial deterioration. During its useful life, material deterioratesand/or is weakened by external events such as mechanical and/or chemicalactions arising from the type of application, repeated usage,hurricanes, earthquakes, storage, transportation, and the like; thus,raising safety, operational, functionality, and serviceability issues.The list of typical material includes, but is not limited to, aircraft,bridges, cranes, drilling rigs, frames, chemical plant components,engine components, oil country tubular goods (herein after referred toas “OCTG”), pipelines, power plant components, rails, refineries,rolling stoke, sea going vessels, service rigs, structures, vessels,workover rigs, other components of the above, combinations of the above,and similar items.

Material owners perform a remaining useful life (herein after referredto as “RUL”) estimation (herein after referred to as “RULE”)occasionally, often following a component failure. This RULE is mostlybased on as-designed data occasionally supplemented by Non-DestructiveInspection (herein after referred to as “NDI”) data. Often, the absenceof an NDI indication comprises the entire fitness for service assessment(herein after referred to as “FFS”) and RULE. NDI is typically carriedout in order to verify that the material deterioration, from some of theknown deterioration causes, has not reduced the material strength belowthe minimum application requirements.

Since its inception in the early 1900s, the NDI industry has utilized avariety of techniques and devices, alone or in combination with eachother, with the majority based on the well known and well documentedtechniques of magnetic flux leakage (herein after referred to as “MFL”),eddy-current (herein after referred to as “EC”), magnetic particle,ultrasonic (herein after referred to as “UT”) radiation, such as x-rayand gamma ray, dye penetrant, and dimensional as well as visual andaudible techniques. MFL and EC are also known as ElectroMagneticInspection (herein after referred to as “EMI”). Typical NDI devicesdeploy a single sensor per material area and are therefore classified asone-dimensional (herein after referred to as “1D”, “1D-NDI” and“1D-EMI”).

However, the limited data 1D-NDI provides for theMaterial-Under-Inspection (herein after referred to as “MUI”) does notadequately address the demanding material application RUL needs. Afterall, a century ago there was no drilling a 20,000 foot well in 10,000feet of water in search for hydrocarbons or trains traveling at speedsin excess of 100 miles per hour or supersonic aircraft. For example,when 1D-NDI does not detect any corrosion pitting that exceeds itsminimum detection capabilities, it is false to conclude that thematerial is fit for the application or its RUL satisfies the applicationneeds. It is desirable therefore to provide Autonomous RULE (hereinafter referred to as “AutoRULE”) equipment and methods to the industry.AutoRULE must detect and recognize the “as-built” and/or “as-is” MUIfeatures impacting its RULE including, but not limited to,imperfections.

The Distinction Between RULE Assessment and NDI

As carried out since its inception, NDI is examining the MUI for signals(flags) that exceed a preset threshold level while common MUI features,such as welds and couplings, typically saturate the NDI processing andthey are ignored by the inspector, similar in appearance to elements191A and 191B of FIG. 19B. Therefore, the end result of an NDI can besummarized as “within the limitations of the inspection technique(s),there were no material regions that gave rise to signals above thethreshold level that were relevant according to the opinion of theinspector”. As will be discussed further, the combination of sensorsignal filtering and threshold prior to any signal evaluations createsdetection dead-zones, a standard NDI practice never the less. Suchfilter/threshold combination can be found throughout the patent record,such as in the 1931 U.S. Pat. No. 1,823,810 and the 2003 U.S. Pat. No.6,594,591. Therefore, the absence of an NDI indication does notnecessarily imply that the material is fit for service or meets theapplication RUL needs.

Another example of an NDI technique with different type detectiondead-zones is Time of Flight Diffraction (herein after referred to as“TOFD”) of U.S. Pat. Nos. 6,904,818, 7,082,822, 7,104,125 used for theinspection of marine drilling risers. The near-surface TOFD dead zone isdue to lateral waves and the far-surface TOFD dead zone is due toechoes. It should be noted that the major and minor axis surfaces ofmarine drilling risers experience the maximum vortex-induced-vibration(herein after referred to as “VIV”) loads and thus, cracking is expectedto initiate at stress concentrators within the TOFD dead-zones, like thebottom of surface pits or the heat affected zone of welds. From actualfatigue and crack growth field runs, Stylwan has concluded that weldcracks tend to grow preferentially parallel to the surface (increaselength) than into the wall (increase depth) and therefore would remainundetected by TOFD while undergoing their most rapid growth. The TOFDdead-zones are significant on used material, typically exceeding themaximum allowed imperfection depth. Therefore, the absence of a TOFDindication can be summarized as “there were no material regions withcracks deeper than the TOFD detection dead-zones” which by no meansconstitute a sound NDI on used material much less an FFS and/or a RULE.

On the other hand, RULE must examine and evaluate, as close as possible,100% of the Material-Under-RUL-Assessment (herein after referred to as“MUA”) for 100% of features spanning from fatigue (2-D) all the way towall thickness changes (A-WDS) and declare the MUA fit for continuingservice and estimate its RUL only after all the features impact upon theMUA have been evaluated. It is well known that the presence of anyimperfection alters the FFS of the MUA and impacts its RUL. Thus, itshould be appreciated that the deployment of the AutoRULE would increasethe overall safety and reliability as it would lead to MUA repair and/orreplacement prior to a catastrophic failure as well as it will reduceand/or eliminate its premature replacement due to concerns when theconventional inspection periods are spaced far apart and/or when theconventional inspection provides an insignificant inspection coverage.In addition, it should be understood that material free of anyimperfections may still not be fit for service in the particularapplication and/or deployment or it may have a shorter RUL.

There is a plethora of 1D-NDI systems in the patent record using termssuch as, “Detect”, “Identify”, “Recognize” but only in the context thatthe sensor signal exceeds the preset threshold level and an indicationis shown in the 1D-NDI readout device. The 1D-NDI readout deviceindication prompts the inspector to assign the material to theverification crew for further manual investigation. However, as shownfurther in FIGS. 2A and 2B, 1D-NDI cannot “connect or associate or knowby some detail” the feature or even if the sensor signal is indeedassociated with a feature; a task assigned entirely to the manualverification crew. As opposed to 1D-NDI, the present invention also usesterms such as, “Identify” and “Recognize” in the context of “connect orassociate or know by some detail”. As shown further in FIGS. 2C and 2D,AutoRULE “knows by some detail” the imperfection and “connects andassociates” the imperfection with known imperfection definitions.AutoRULE preferably uses FFS and RUL formulas and knowledge and ispreferably able to export a file for use by a finite element analysisengine (herein after referred to as “FEA”) because AutoRULE “knows bysome detail” the material features, as shown in FIGS. 3A through 3D. Itshould be understood that different FEA engines use different structuregeometry import/export specifications.

SUMMARY OF THE INVENTION

In one possible embodiment, an evaluation system may be provided toascertain and/or to mitigate hazards arising from the failure of amaterial resulting from misapplication and/or deterioration of thematerial shortening its RUL. The system may comprise elements such as,for instance, a computer and a material features acquisition system. Thematerials feature acquisition system may be used to scan the materialand identify the nature and/or characteristics of material features. Inone possible embodiment, the invention may further comprise a databasewhich may comprise material historical data and/or constraints. Thefirst database constraints may be selected at least in part fromknowledge and/or rules. The knowledge and/or rules may involve stress orloading related factors. A non-limiting list of knowledge or rules mayinvolve use of the material in applications involving one or more ofbending, buckling, compression, cyclic loading, deflection, deformation,dynamic linking, dynamic loading, eccentricity, eccentric loading,elastic deformation, energy absorption, feature growth, featuremorphology migration, feature propagation, impulse, loading,misalignment, moments, offset, oscillation, plastic deformation,propagation, shear, static loading, strain, stress, tension, thermalloading, torsion, twisting, vibration, and/or a combination thereof.

In another embodiment, a first computer program may evaluate the impactof the material features upon the material by operating on the materialfeatures. The operation may be guided by the database constraints and/orany material historical data. In one possible embodiment, the firstcomputer program evaluates the RUL of the material under theconstraints.

In one embodiment, an evaluation system may provide a computerprogrammed to calculate the remaining useful life of a material, andrespond in various ways. For instance, the computer may be programmed tooperate/process or otherwise act upon a first material feature, whichmay be electronically or otherwise detected, to recommend a remediationpath to extend said remaining useful life. The material remediation pathrecommended by the programmed computer may, for example, comprise atleast of utilization, redeployment and alteration to a shape of thematerial feature. The alteration to a shape of said material feature isan optimal shape for extending a remaining useful life.

In another embodiment, sound such as speech or special audio effects maybe utilized by the computer in different ways such as requestinginformation of various types about the material under investigation orproviding information about it. For instance, the computer may utilize asound synthesizer to convert calculated information about the remaininguseful life into speech or easily recognizable audio effects.

In another embodiment, a first computer program may evaluate the impactof the material features upon the material by operating on the materialfeatures. The operation may be guided by the database constraints and/orany material historical data, stored, at least in part, in a storagedevice affixed on to the material. In one possible embodiment, the firstcomputer program evaluates the RUL of the material under the constraintsand writes, at least in part, the evaluation data, including but notlimited to, inspection data and/or FFS data and RUL data.

In another possible embodiment, a material evaluation system maycomprise a computer, a material features acquisition system, a firstdatabase comprising of constraints and/or material historical data;and/or a data conversion program, whereby the material features may berendered in a data format for use by a finite element analysis engine.

In another possible embodiment, the invention may comprise a sensor withan output comprising of signals indicative of features from the materialbeing scanned, in a time-varying electrical form. A sensor interface maybe provided for the computer, wherein the computer converts the signalsto a digital format. Additional elements may comprise at least onedatabase comprising of material features recognition constraints and/orhistorical data. A computer program may be executed on the computer foridentifying the material features detected by said sensor.

In another possible embodiment, a material evaluation system maycomprise a computer and a material features acquisition system, wherebythe material features are acquired and are stored as part of a researchand development effort to establish FFS and RUL using actual materialdeployment and application data.

In another embodiment, a method may be provided to calibrate a remaininguseful life evaluation system comprising steps such as, for example,providing at least one material sample, with at least one feature, andpossibly many features, that impact a material remaining useful life,and whereby a remaining useful life evaluation outcome of the materialsample is known.

Additional steps may comprise evaluating the material sample with saidremaining useful life evaluation system, and adjusting the remaininguseful life evaluation system, whereby an evaluation outcome of saidmaterial sample matches a known remaining useful life of said materialsample.

These and other embodiments, objectives, features, and advantages of thepresent invention will become apparent from the drawings, thedescriptions given herein, and the appended claims. However, it will beunderstood that above-listed embodiments and/or objectives and/oradvantages of the invention are intended only as an aid in quicklyunderstanding certain possible aspects of the invention, are notintended to limit the invention in any way, and therefore do not form acomprehensive or restrictive list of embodiments, objectives, features,and/or advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a block diagram of an 1D-EMI non-destructiveinspection system.

FIG. 2A illustrates a 1D-EMI inspection trace for a mid-wallimperfection.

FIG. 2B illustrates a 1D-EMI inspection trace for machined (man-made)calibration notches.

FIG. 2C illustrates the flaw spectrum of the mid-wall imperfection ofFIG. 2A.

FIG. 2D illustrates the flaw spectrum of the machined (man-made)calibration notches of FIG. 2B.

FIG. 3A illustrates a section of MUI with an imperfection.

FIG. 3B illustrates a section of MUI following remediation.

FIG. 3C illustrates a section of MLII following incomplete remediation.

FIG. 3D illustrates the stress concentration.

FIG. 4 illustrates a block diagram of the AutoRULE system according tothe present invention;

FIG. 5 illustrates a block diagram of the AutoRULE system and the speechand sound interface according to the present invention;

FIG. 6 illustrates a block diagram of a speech synthesizer, a soundsynthesizer and a Speech recognition engine;

FIG. 7 illustrates a block-diagram of the inspection sensorpre-processor and the filter arrangement according to the presentinvention;

FIG. 8A illustrates a programmable gain amplifier according to thepresent invention;

FIG. 8B illustrates the design mathematical formula for the programmablegain amplifier of FIG. 8A according to the present invention;

FIG. 9A illustrates a programmable 3^(rd) order low-pass filteraccording to the present invention;

FIG. 9B illustrates the design mathematical formula for a 1 ^(st) orderlow pass filter of FIG. 9A according to the present invention;

FIG. 8C illustrates the design mathematical formula for a 2^(nd) orderlow pass filter of FIG. 9A according to the present invention;

FIG. 10A illustrates a programmable band-pass filter and a 3^(rd) orderhigh-pass filter according to the present invention;

FIG. 10B illustrates the design mathematical formula for a 1^(st) orderhigh-pass filter of FIG. 10A according to the present invention;

FIG. 10C illustrates the design mathematical formula for a 2^(nd) orderhigh-pass filter of FIG. 10A according to the present invention;

FIG. 11A illustrates the Bilinear Transformation, a mathematicaltechnique to translate an analog transfer function to the digitaldomain, according to the present invention;

FIG. 11B illustrates the mathematical formula for the BilinearTransformation illustrated in FIG. 11A according to the presentinvention;

FIG. 11C illustrates a mathematical formula for the frequency responseof IIR Digital filter for the Bilinear Transformation illustrated inFIG. 11A according to the present invention;

FIG. 12A illustrates the block-diagram to implement the discrete wavelettransform decomposition through digital filter banks according to thepresent invention;

FIG. 12B illustrates a mathematical formula for a low-pass filter of aHAAR wavelet of FIG. 12A according to the present invention;

FIG. 12C illustrates a mathematical formula for a high-pass filter of aHAAR wavelet of FIG. 12A according to the present invention;

FIG. 13 illustrates a block diagram of the signal processing of AutoRULEsystem according to the present invention;

FIG. 14 illustrates a flow chart of a typical RULE assessment accordingto the present invention;

FIG. 15 illustrates a typical RULE assessment time sequence according tothe present invention;

FIG. 16A illustrates a typical material sample with man-made features;

FIG. 16B illustrates a typical material sample with a critically flawedarea;

FIG. 16C illustrates typical reference defects found in 1D-NDIstandards;

FIG. 16D a critically flawed area;

FIG. 17 illustrates a block diagram of a typical NDI process;

FIG. 18 illustrates a block diagram of the AutoRULE process according tothe present invention;

FIG. 19A illustrates an AutoRULE computer readout for use in FFS and RULdata gathering; and

FIG. 19B illustrates an AutoRULE computer readout configured for drillpipe.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The following Trademarks are referred to herein below in alphabeticalorder:

Compact Flaw Spectrum, CoilBOT, CyberCHECK, Cyberinspector, CyberSCAN,CyberSCOPE, Defect Numerical Analysis, Flaw Defining Dimension, FDDim,Flaw Spectrum, InspectionBOT, LineBOT, Material Status DescriptiveValue, MSDV, RailBOT, Rig Data Integration System, RDIS-10, RiserBOT,STYLWAN and WellBOT are trademarks of STYLWAN Incorporated.

OCI-5000 series and OCI are trademarks of OLYMPIC CONTROL, Incorporated.

To understand the terms associated with the present invention, thefollowing descriptions are set out herein below. It should beappreciated that mere changes in terminology cannot render such terms asbeing outside the scope of the present invention.

Autonomous: able to perform a function without external control orintervention.

Classification: assigning a feature to a particular class.

Compact Flaw Spectrum: a condensed presentation of Flaw Spectrum orFrequency Flaw Spectrum data. The STYLWAN Compact Flaw Spectrum andtrace color assignments is set out herein below and spans from wallthickness (3-DC) to microcracking (2-DC): C-3D (blue), C-3d (green),C-2d (red) and C-2D (magenta) and Geometry variations 3-G (yellow).Constraints: controls in doing something. Constraints include, but arenot limited to knowledge, rules, boundaries and data.

Decomposed in Frequency: Separating desirable characteristics from afrequency response gathered during an evaluation process.

Defect: an imperfection that exceeds a specified threshold and maywarrant rejection of the material.

Degradation Mechanism: the phenomenon that is harmful to the material.Degradation is typically cumulative and irreversible such as fatiguebuilt-up.

Essential: important, absolutely necessary.

Expert: someone who is skilful and well informed in a particular field.

Feature: a property, attribute or characteristic that sets somethingapart.

Finite Element Analysis, FEA: a method to solve the partial or ordinarydifferential equations that guide physical systems.

FEA Engine: is an FEA computer program, a number of which arecommercially available such as Algor and Nastran. In practice, FEAengines are used to analyze structures under different loads and/orconditions, such as a marine drilling riser under tension and enduringvortex induced vibration. An FEA engine may analyze a structure with afeature under static and/or dynamic loading, but not a feature on itsown.

Fitness For Service: typically an engineering assessment to establishthe integrity of in service material, which may or may not contain animperfection, to ensure the continuous economic use of the material, tooptimize maintenance intervals and to provide meaningful remaininguseful life predictions. In the prior art, RULE assessment was typicallyperformed by an expert or a group of experts. Typically, an RULEassessment is based primarily on as-designed data while the AutoRULEassessment is based primarily on as-built or as-is data. When designdata is available, AutoRULE also monitors compliance with the designdata. When less than optimal data is available, AutoRULE may perform aFitness For Service Screening.

Flaw Defining Dimension: (Herein after referred to as “FDDim”) typicallythe flaw dimension and/or projection perpendicular (transverse) to themaximum stress. The extraction matrix calculates FDDim. The extractionmatrix was published in 1994 and it is beyond the scope of this patent.

Flaw Spectrum: a presentation of data derived from an extraction matrix.The STYLWAN Flaw Spectrum and trace color assignments is set out hereinbelow and spans from wall thickness (A-WDS) to microcracking (2-D):A-WDS (maroon), R-WDS (black), 3-D (blue), 3-d (cyan), C (green), 2-d(red) and 2-D (magenta) and Geometry variations 3-G (yellow). Whennecessary, categories are further subdivided to α, β and γ, such as2-da. It should be understood that the one to one correspondence ofsimple imperfections to the STYLWAN Flaw Spectrum occasionally appliesto machined (man-made) imperfections and not to the complex formimperfections typically found in nature. Therefore, the STYLWAN FlawSpectrum elements must be viewed as an entity identification signature,just like DNA, but not as a detailed chemical analysis. It should beappreciated that mere changes in terminology and/or regrouping and/orrecategorizing cannot render such terms as being outside the scope ofthe present invention.

Frequency Based Flaw Spectrum: a presentation of data derived fromone-dimensional or two-dimensional sensor in combination with filterbanks to decompose, interpret and categorize the sensor receivedinformation in a fashion substantially similar to the flaw spectrum. Itshould be understood that any further processing, such as the AutoRULEprocessing, utilizes the Flaw Spectrum regardless of its origin andderivation method.

Imperfection or Flaw: one of the material features—a discontinuity,irregularity, anomaly, inhomogenity, or a rupture in the material underinspection.

Knowledge: a collection of facts and rules capturing the knowledge ofone or more specialist.

Normalization: Amplitude, and/or phase, and/or bandwidth, and/or timeshifting adjustments of the inspection sensor output to compensate forthe system implementation idiosyncrasies that affect the features sensoroutput such as changes/differences due to scanning speed and/orimplementation geometry and/or excitation and/or for responsecharacteristics of the inspection sensor.

Productivity: The total amount of material undergone assessment orevaluation. The productivity rate is defined as the ratio of amount ofmaterial undergone assessment or evaluation over the amount of time toperform such assessment or evaluation.

Remaining Useful Life: a measure that combines the material conditionand the failure risk the material owner is willing to accept. The timeperiod or the number of cycles material (a structure) is expected to beavailable for reliable use.

Remaining Useful Life Estimation: establishes the next monitoringinterval (condition based maintenance) or the need for remediation butit is not intended to establish the exact time of a failure. When RULEcan be established with reasonable certainty, the next monitoringinterval may also be established with reasonable certainty. When RULEcannot be established with reasonable certainty, then RULE may establishthe remediation method and upon completion of the remediation, the nextmonitoring interval may be established. When end of useful life isestablished with reasonable certainty, alteration and/or repair and/orreplacement may be delayed under continuous monitoring.

Response Characteristics Desirable characteristics separated from afrequency response to be evaluated preferably by a computer to determineimperfections. Rules: how something should be done to implement thefacts.

Scanning Speed: The speed of the material passing the sensor (or thespeed of the sensor along the material).

1D-EMI Inspection Equipment Description

FIG. 1 illustrates a block diagram of an eight channel 1D-EMI inspectionsystem similar to the one in U.S. Pat. No. 2,685,672 utilizing the MFLprinciple. In particular, the sensors and their arrangement as describedin 672 FIGS. 5 and 6 are still in use with hundreds of units employedworldwide in portable or stationary configurations. The same sensorconfiguration is also illustrated in FIG. 7 of U.S. Pat. No. 2,881,386and similar sensors configuration is also used in the pipeline pig ofU.S. Pat. No. 3,225,293.

The magnetizing coil 3 of the inspection head 2 induces excitation intoMUI 1. It should be understood that the magnetic field can be applied inany direction. U.S. Pat. No. 2,685,672 shows the induction of alongitudinal magnetic field while U.S. Pat. No. 3,202,914 shows theinduction of a transverse magnetic field. It should further beunderstood that one or more permanent magnets may be use instead of amagnetizing coil or a combination thereof. The inspection sensors 4signals 4A through 4H are processed by the high-pass filters 11A through18A to eliminate low frequencies and any dc components. The signals 4Athrough 4H are then amplified by amplifiers 11B through 18B and are thenfiltered by the low-pass filters 11C through 18C to eliminate highfrequencies. The highest signal selector 10 compares the highest of theband-limited signals 4A through 4H to a preset threshold level andeliminates all signals below the threshold level. Thus, the inspectiontrace 5 that is presented to the inspector typically shows the frequencyband-limited highest signal that exceeds a preset threshold level. Thistype of signal acquisition and processing creates detection dead-zonesand it is not suitable for RULE assessment or screening.

The MFL principle of operation is eloquently described in U.S. Pat. No.2,194,229: “It is old in the art to test magnetic material for flaws bypassing therethrough a magnetic flux, providing means responsive tovariations in the flux, and thereby locating regions of abnormalmagnetic reluctance”; and herein lies the problem that has plagued the1D-NDI all along. 1D-EMI units flag “ . . . regions of abnormal magneticreluctance” in ferromagnetic materials and UT units flag regions ofechoes. They do not identify the material features; they do not detectthe failure-potential of any feature, including but not limited toimperfection, and most importantly, they do not assess the materialfitness for service under the application constraints or the materialRUL. Instead, they rely upon an inspector to monitor and interpret theMFL or UT traces and instruct a manual verification crew to locate theflagged “ . . . regions of abnormal magnetic reluctance” or echoes onthe MUI for further manual investigation, but only for MUI regions thatgive rise to signals that exceed a preset magnitude threshold, a 1D-NDIshortcoming that can still be found, for example, in U.S. Pat. No.6,594,591 FIG. 9 and will be discussed in detail further below. Thus,OCTG owners typically specify that the verification crew investigate atleast ±six inches on either side of an indication. It is not uncommonfor the verification crew to miss entirely the flagged MUI region oreven the flagged MUI from a simple miscount. This manual verificationproblem is exemplified on pipelines that are miles long or railroads, atwo vehicle inspection/verification solution described in U.S. Pat. No.5,970,438.

Once an imperfection is located by the verification crew and sufficientmeasurements are recorded, the information is forwarded to the owner ofthe MUI to decide its disposition. In order to decide the disposition ofthe MUI, the owner preferably performs an RULE assessment with thelimited data the verification crew was able to gather. Often, a singlepass/fail approach is implemented.

It is therefore desirable to provide means to retrofit AutoRULE to thehundreds of 1D-EMI units deployed worldwide. It is imperative therefore,that AutoRULE detects and recognizes the “as-is” MUA features impactingits FFS and RUL including, but not limited to, imperfections. Theimperfection recognition was discussed in the AutoNDI prior applicationSer. No. 10/995,692 (U.S. Pat. No. 7,155,369) using the extractionmatrix and application Ser. No. 11/079,745 (U.S. Pat. No. 7,231,320)using spectral analysis to derive a frequency based flaw spectrum forfurther use by the AutoNDI.

A Brief 1D-EMI History

The one to one correspondence of FIG. 1 1D-EMI elements to the elementsillustrated in FIG. 1 of U.S. Pat. No. 1,823,810 is as follows: Amagnetic field (excitation) is induced into MUI 1 (810 FIG. 1magnetizable material 6) by a coil 3 (810 FIG. 1 exciting coil 14). Thesensor 4 (810 FIG. 1 search coil 19) signal is processed by thehigh-pass filter 11A (810 FIG. 1 capacitor and resistor connected to thegrid of the vacuum tube) and it is then amplified by amplifier 11B (810FIG. 1 dual triode vacuum tube) and presented to the inspector (810 FIG.1 indicator 21) instead of an inspection trace 5. The limited frequencyresponse of (810 FIG. 1 indicator 21) acts as a lowpass filter 11C.Since U.S. Pat. No. 1,823,810 depicts a single channel NDI system, thereis no need for a highest signal selector 10. However, the sensor 4 (810FIG. 1 search coil 19) signal is compared to an operator adjustablethreshold level (810 FIG. 1 the resistor connected to the grid of thefirst vacuum tube is connected to a negative (threshold) voltage). Onlysensor signals that exceed this threshold (negative voltage) wouldpropagate and be shown to the inspector (810 FIG. 1 indicator 21).

The prolific 1D-EMI unit of U.S. Pat. No. 2,685,672 essentially consistsof eight U.S. Pat. No. 1,823,810 channels with the addition of a highestsignal selector. It should be understood that 1D-EMI units consisting oftwo to forty eight channels have also been constructed and the number ofchannels any 1D-EMI deploys should not be interpreted as a limitation tothis invention. In the 1960s the vacuum tubes were replaced bytransistors, as shown in U.S. Pat. No. 3,202,914 FIG. 6, and in the1970s by integrated circuit amplifiers. Meters and chart recorders wereused for the operator readout until the mid 1980s when they werereplaced by computers with their colorful displays and printouts.However, no matter how sophisticated the operator readout is, it willnever show information that was lost during the acquisition andprocessing of the sensor signals.

The brief 1D-EMI history shows that although the electronic circuitshave followed the advances in technology, the inspection philosophy andmethods have not. The 1D-EMI limitations and pitfalls of a century agostill plague the modern 1D-EMI, regardless of the inspection techniqueused. For example, U.S. Pat. No. 6,594,591 applies the combination ofsensor signal filtering and threshold prior to any signal evaluation toboth EMI and UT.

1D-EMI Loss of Sensor Signal Frequency Spectrum Information

As discussed earlier, the 1D-EMI high-pass filters 11A through 18Aeliminate low frequencies and dc components for system stability and thelow-pass filters 11C through 18C to eliminate high frequencies to removethe “noise”. Useful frequency components of the sensor signal aretherefore discarded before being evaluated and any useful informationthey may contain is prematurely and irreversibly lost rendering thistype of signal acquisition and processing unsuitable for AutoRULE.Referring to FIG. 6 of U.S. Pat. No. 3,202,914, capacitor 51 and itsassociated components form a high-pass filter that prematurely andirreversibly discards low-frequency components of the sensor signalwhile capacitor 48 and its associated components form a low-pass filterthat prematurely and irreversibly discards high-frequency components ofthe sensor signal. Other such examples can be found in U.S. Pat. No.2,582,437 (see FIG. 1 capacitor 13 and resistor 40); in U.S. Pat. No.1,823,810 (see FIG. 1, amplifier 20) as well as in U.S. Pat. No.5,671,155 (see FIG. 1, AC-couplers 6) and U.S. Pat. No. 5,943,632 (seeFIG. 1, AC-couplers 6). Another such example using digital filters isshown in FIG. 8 of U.S. Pat. No. 5,371,462 showing a “ . . . flow chartof an algorithm for pre-processing to remove DC and low frequencycomponents” from the sensor signal.

Scanning Speed Effects on the Sensor Signal

U.S. Pat. No. 2,770,773 also encompasses many elements of the above todetect corrosion pitting and clearly states a frequency spectrumprocessing essential element: the imperfection frequency spectrum versusscanning speed interdependence. The high-pass filters of FIG. 7(capacitors 66, 67 and resistors 69, 70) remove many unwanted “ . . .signal producing variables such as separation from the casing wall, wallroughness, misfit . . . ” [Column 6, Line 15]. Following the high-passfilter is a band-pass filter “ . . . to pass frequencies in the bandbetween about 3 and 20 cycles per second, as this is the characteristicfrequency range of signal due to the passage of the shoe 15 across acasing corrosion pit at a transverse speed of twenty feet per minute.This frequency band related to the speed of traverse of the instrument10 through the casing 12 will, of course, be varied to suit any othertraverse speed selected” [Column 6, Line 33]. Therefore, it is wellknown in the art that the same imperfection will appear differently inthe sensor signal frequency spectrum depending on the scanning speed. Itis also well known in the art that fixed frequency filters alwayspass/discard the same frequency band, thus 1D-EMI systems, such as theones in U.S. Pat. Nos. 5,671,155 and 5,943,632, always propagate forfurther processing undefined frequency components of the sensor signalagain, rendering this type of signal acquisition and processingunsuitable for AutoRULE.

Another early observation of the NDI industry is the scanning speedversus signal amplitude proportional interdependence for coil sensors.U.S. Pat. No. 2,881,386 (see FIGS. 10 and 11) provides a technique foramplitude compensation for the scanning speed variations.

AutoRULE can only be carried out when the MUA features, including butnot limited to imperfections, are recognized and are identified.Automatic features recognition demands that the features signalamplitude and frequency spectrum be compensated for the idiosyncrasiesof the scanning system and the effects of the different scanning speeds.It is one possible objective of this embodiment of the invention todetermine the inspection system response characteristics, to track thescanning speed and preserve, naunalize and automatically analyze thesensor signal frequency spectrum for all the spectrum components thatinclude non-redundant information spanning from Fatigue to wallthickness.

1D-NDI Calibration Limitations

FIG. 2A illustrates the 1D-NDI inspection trace 5 of an OCTG that failedat imperfection 5B. The OCTG had two mid-wall imperfections 5A and 5Band failed during hydrotesting. Prior to assembly into a marine drillingriser, the OCTG was inspected by a state of the art 1D-NDI. The 1D-NDIsystem was calibrated using a calibration joint with machined notches, a1D inspection industry standard but faulty practice further illustratedin FIG. 16C. FIG. 2B illustrates the 1D-NDI inspection trace of acalibration notch 5C.

FIG. 2C illustrates the flaw spectrum of the same OCTG mid-wallimperfections 6A and 6B, corresponding to 5A and 5B, and FIG. 2Dillustrates the Stylwan flaw spectrum of the calibration notch 6C,corresponding to 5C. The reason of this failure can easily be deducedfrom FIGS. 2C and 2D. The Stylwan flaw spectrum of FIG. 2C clearly showsthat the mid-wall imperfections 6A and 6B are utterly unrelated to thecalibration notches 6C of FIG. 2D. It is also easy to see how 1D-NDIwould mislead someone to believe that the mid-wall imperfections 5A and5B of FIG. 2A are somehow related to the calibration notches 5C of FIG.2B and setup the 1D-NDI equipment erroneously, having no way of knowingany better (Knowing that the high threshold level set by the calibrationwill hinder the detection of the mid-wall imperfections 5A and 5B with1D-NDI until they burst during hydrotesting). Imperfections 5A and 5Bwere missed by 1D-NDI because their signal amplitude did not exceed thethreshold level that was erroneously set to detect machined calibrationnotches. It should also be noted that when a single pass/fail measure isutilized, it would eventually lead to equipment that focus on passingthe particular single measure. This is also the case with 1D-NDI. Closerscrutiny of the 1D-NDI sensor structure and signal processing would showthat both are fine tuned to pass the calibration notches test while theyare likely to miss imperfection 7B of FIG. 3, yet another 1D-NDI problemroot cause. It is another possible objective of an embodiment of theinvention to establish a scanning/inspection system calibration meansand methods adept for AutoRULE

1D-NDI Remediation Limitations

FIG. 3A illustrates a section of MUI with an imperfection 7A. A typical1D-NDI remediation practice states: “An external imperfection may beremoved by grinding . . . . Where grinding is performed, generous radiishall be employed to prevent abrupt changes in wall thickness . . . .The area from which the defect is removed shall be reinspected . . . toverify complete removal of the defect”. This statement furtherillustrates the limitations of 1D-NDI.

“Grinding” actually does not “remove” an imperfection. It just shiftsthe imperfection 7A morphology (shape) from one with high stressconcentration 8A (due to the “abrupt changes in wall thickness”) toimperfection 7B with lower stress concentration 8B (due to the “generousradii”). For example, if the depth of the original external imperfection7A was 10% of the material wall thickness, the wall loss in the OCTGregion 7B would still be 10% (or greater) even after the imperfection 7Awas morphed (“completely removed”) into 7B by “grinding”, resulting inan OCTG with altered FFS and reduced RUL.

As discussed earlier, the 1D-EMI high-pass filters 11A through 18Aeliminate low frequencies and dc components and therefore prematurelyand irreversibly eliminate imperfection 7B information thus, creating“detection dead-zones” misleading great many to believe and actuallyverify the “complete removal of the defect”, when in fact, theform-shifted “external imperfection” 7B is still clearly visible withthe naked eye and the wall loss is still 10% (or more). If imperfection7B was the result of OCTG stretching, such as a neckdown, instead ofgrinding, 1D-NDI would miss imperfection 7B entirely and classify theOCTG with the reduced cross sectional area erroneously. Strength ofmaterial knowledge teaches that the reduced cross sectional area of thematerial reduces the ability of the material to absorb energy thusaltering its FFS and reduces its RUL.

FIG. 3C illustrates a dangerous condition where imperfection 7A waspartially morphed leaving behind a failure seed 7C with increased stressconcentration 8C. A similar example is shown in FIG. 16D element 159.1D-NDI would miss imperfection 7C as a result of the 1D-NDI detectiondead-zones arising from the combination of filters and threshold. Itshould be understood that this recommended 1D-NDI remediation methoddoes not take into account the imperfection neighborhood nor does itoptimize the FFS or RUL of the OCTG. It is yet another possibleobjective of an embodiment of the invention to establish remediationmeans and methods adept for AutoRULE.

1D-NDI Magnitude Threshold Versus Imperfection Pattern Recognition

As FIG. 2C illustrates, the Stylwan flaw spectrum detection ofimperfections 6A and 6B is based on pattern recognition, not signalamplitude alone. Therefore, failure seeds, like imperfection 6A, can bedetected early on regardless of their signal amplitude.

By now, it should be easy to recognize the calibration notches 6C.However, those notches were machined on new defect-free material andthey meet strict geometry standards, as it is further shown in FIG. 16C.Therefore, their flaw spectrum signature is extremely simple and easilyrecognizable. On the other hand, imperfections in nature are mostlyfound on used material, they are rarely alone, they are multifaceted andgive rise to complex flaw spectrums that are not always easilyrecognizable. Furthermore, a key weaknesses of any manual process, suchas the manual verification, is the uncontrollable “human factors”. Ifimperfection 6A was found instead on heavily used material along withother imperfections, would a trained inspector always distinguish it inthe resulting flaw spectrum clutter? It is the aim of this invention toanswer this question with confidence by providing a computer, a sensorinterface and a program to scan the sensor signals for patterns torecognize material features, including but not limited to imperfections.Again, features recognition demands that the frequency spectrum of thesensor signals that include non-redundant information spanning fromFatigue to wall thickness is preserved and normalized.

Root Cause Identification Versus Simplistic Explanation

It should be apparent from the above that the 1D-NDI detectiondead-zones, limitations and pitfalls of a century ago do not adequatelyaddress the material needs of the modern applications and they fallshort in active failure prevention. Again, a century ago there was nodrilling a 20,000 foot well in 10,000 feet of water in search forhydrocarbons or trains traveling at speeds in excess of 100 miles perhour or supersonic aircraft. These detection dead-zones, limitations andshortcomings of the 1D-NDI lead to a futile long term cycle as detailedbelow.

Often, when a failure occurs, the focus is on repairing/replacing thedamaged material as rapidly as possible in order to reduce downtime andat the lowest possible cost. Occasionally, the obligatory “why?” isasked and a simplistic explanation like “fatigue cracks are a fact oflife” is accepted as an adequate answer; a human decision that may leadto a catastrophic failure much later. Occasionally, an inspector or evena 1D-NDI service provider may be replaced with another one using theexact same methods and equipment. One should bear in mind the heavydependence of 1D-NDI upon the inspector and the industry desire topreserve the 1D-NDI equipment “reputation”. At some point, someoneexamines the number of failures over the years and discovers that thereis a compatible number of failures with 1D-NDI as it is without 1D-NDI.The simplistic explanation then is that NDI is a pointless expense andit is therefore reduced or bypassed entirely; yet another human decisionthat may lead to a catastrophic failure much later. For example, themanufacturer and the owner of the marine drilling riser depicted inFIGS. 2A through 2D may reach such a conclusion. The compound effect ofthose decisions, often spanning many years, eventually leads to aspectacular catastrophic failure somewhere. The simplistic explanationfor this spectacular failure is easily identified as the reduced orbypassed NDI and the simplistic motive is identified as “greed”. Again,it should be noted that this string of latent root-causes typicallyspans many years and possibly different groups of individuals making itdifficult, if not impossible, to pinpoint its origins. The “greed”simplistic explanation however, is readily accepted and after theobligatory hearings, firings and fines, 1D-NDI is mandated starting thevicious cycle all over again. The increased awareness is typicallyshort-lived.

However, this approach treats the results of a problem and does not seekto identify and analyze the root-cause of the problem. Unless anexcavator accidentally hits a pipeline for example, pipeline materialdeterioration occurs over time eventually leading to a failure. There isno single deterioration root-cause acting equally upon a 500 milepipeline for example, with some of it falling within the 1D-NDIdetection dead-zones. Along the pipeline length, different deteriorationroot-causes may be acting upon the pipeline resulting in differentdeterioration rates and different segment RUL, but 1D-NDI is inherentlyincapable of effectively identifying those root-causes as illustrated inFIGS. 2A and 2B. The objective of this invention to recognize features,including imperfections, is the first step in identifying the root-causeof material deterioration leading to effective failure preventive actionand thus, extending the material RUL.

Description of AutoRULE Computer

FIG. 4 illustrates an AutoRULE block diagram further illustrating thecomputer 20, the features detection interface 30, the speech and soundinterface 40 and the preferable information exchange among thecomponents of the AutoRULE. It should be understood that the AutoRULEcomputer 20 may include more than just one computer such as a cluster ofinterconnected computers. It should be understood that the computer 20does not necessarily comprise a laptop or portable personal computer andsuch misinterpretation should not be made from the illustrations in thefigures and shall not be read as a limitation herein. The computer 20preferably comprises a display 21, keyboard 22, storage 23, for storingand accessing data, a microphone 27, a speaker 28 and a camera 29. Itshould be understood that the display 21, the keyboard 22, the speaker28 and the microphone 27 may be local to the computer 20, may be remote,may be portable, or any combination thereof. It should be furtherunderstood that camera 29 may comprise more than one camera. Furthercamera 29 may utilize visible light, infrared light, any other spectrumcomponent, or any combination thereof. The camera 29 may be used torelay an image or a measurement such as a temperature measurement, adimensional measurement (such as 3-G of the flaw spectrum), acomparative measurement, character and/or code recognition, such as aserial number, or any combination thereof including information toidentify the MUA 9 and/or the authorized operator through biometricrecognition. It should be appreciated that the storage 23 may comprisehard disks, floppy disks, compact discs, magnetic tapes, DVDs, memory,and other storage devices. The computer 20 may transmit and receive datathrough at least one communication link 26 and may send data to aprinter or chart recorder 24 for further visual confirmation of theinspection data 25 and other related information. It should beunderstood that communication link 26 may be in communication throughwired or wireless means, including but not limited to RFID, opticallinks, satellite, radio and other communication devices. At least onecommunication link 26 may facilitate communication with an expert or agroup of experts in a remote location. The computer 20 preferablyprovides for data exchange with the features detection interface 30 andthe speech and sound interface 40.

Material Identification

At least one communication link 26 may facilitate communication with anidentification system or a tag, such as RFID, affixed to MUA 9. Suchidentification tags are described in U.S. Pat. No. 4,698,631, No.5,202,680 and No. 6,480,811 and are commercially available from multiplesources such as Texas Instruments, Motorola and others. Embedded RFIDtags, specifically designed for harsh environments, are available withuser read-write memory onboard (writable tag). It is anticipated thatthe memory onboard identification tags would increase as well as theoperational conditions, such as temperature, while the dimensions andcost of such tags would decrease.

RFID tags are passive responders, deriving their power from the radiofrequency of the reader, as described in U.S. Pat. No. 2,927,321. Again,all assemblies, subassemblies, components and software for theimplementation of an RFID system are commercially available frommultiple sources. RFID and other tags may be affixed to typical materialthat includes, but is not limited to, aircraft, bridges, cranes,drilling rigs, frames, chemical plant components, engine components,OCTG, pipelines, power plant components, rails, refineries, rollingstoke, sea going vessels, service rigs, structures, vessels, workoverrigs, other components of the above, combinations of the above, andsimilar items. It should be understood that identification systems formost of such material, due to their large size, may comprise of acomputer system attached to the material or multiple such identificationcomputer systems.

The partial material list above comprises mostly of metallic objects andtherefore the identification system tags would most likely be in closeproximity to metals. The proximity to metals creates unique problemsthat must be addressed during the system design and testing time. Forexample, the metal in proximity with the tag and the reader may changethe frequency of the ID system and therefore the system preferably wouldbe designed for the changed frequency. Furthermore, when the tags areembedded into the material, the frequency would preferably be selectedto maximize the read/write penetration, such as lower frequencies. LowerQ-factor antennas would preferably reduce some of the interferenceproblems including the probability of read-write dead zones. Statictesting of the identification system therefore may not accuratelyreproduce and measure the identification system field performance.

Computer 20 preferably provides for data exchange with the materialidentification system, including but not limited to, material ID,material geometry, material database, preferred FEA model, preferredevaluation system setup, constraints, constants, tables, charts,formulas, historical data or any combination thereof. It should beunderstood that identification systems may further comprise of a dataacquisition system and storage to monitor and record FFS and RUL relatedparameters. It should be further understood that the materialidentification system would preferably operate in a stand alone mode orin conjunction with AutoRULE. For example, while tripping out of a well,computer 20 may read such data from the drill pipe or tubingidentification tag and while tripping into a well, computer 20 mayupdate the identification tag memory. It should be understood thatcomputer 20 may apply an excitation bias to the material while trippinginto the well. The excitation bias places the material in a known stateprior to the evaluation. Following the last trip out of the well, theidentification tag of the racked drill pipe or tubing may be updated.Another example would be an identification computer with a dataacquisition system affixed onto a riser joint or a crane. Duringdeployment, such an identification system would preferably monitor andrecord FFS and RUL related parameters, such as pressure, temperature,loads, vibration and the like.

Speech and Voice Control

Speech is a tool which allows communication while keeping one's handsfree and one's attention focused on an elaborate task, thus, adding anatural speech interface to the AutoRULE would preferably enable theoperator to focus on the MUA 9 and other related activities whilemaintaining full control of the AutoRULE. Furthermore, the AutoRULEnatural speech interaction preferably allows the operator to operate theAutoRULE while wearing gloves or with dirty hands as he/she will notneed to constantly physically manipulate the system. Although varioustypes of voice interaction are known in the art, many problems stillexist in an industrial setting due to the potential of an excessivenoise environment. Thus, this invention preferably provides for naturalspeech interaction between the human operator and the AutoRULE capableof deployment under adverse conditions.

FIG. 5 illustrates a block diagram of the AutoRULE system and thenatural speech and sound interface 40 according to the presentinvention. Preferably, a natural speech command is received by themicrophone 27 or other sound receiving device. The received sound ispreferably amplified, such as by the amplifier 72. Amplifier 72 may be aprogrammable gain amplifier 80 as depicted in FIG. 8A. A feature of theembodiment is that the microphone amplifier 72 is followed by a bank ofband-reject notch filters 71. Preferably, the operator and/or thesoftware can adjust the amplifier 72 gain and the center frequency ofthe notch filters 71. Such a notch filter may be constructed by movingthe low-pass filter 90 of FIG. 9A to the output 108 of the high-passfilter 100 of FIG. 10A. Since industrial noise is primarily machinegenerated, it typically consists of a single frequency and itsharmonics. Therefore, adjustable notch filters 71 are well suited forthe rejection of industrial noise. The notch filters 71 are preferablyfollowed by the speech and sound recognition engine 70. The data fromthe speech and sound recognition engine 70 is preferably exchanged withthe computer 20. Data from the computer 20 may be received by a soundsynthesizer 50 and a speech synthesizer 60. The data received by thespeech synthesizer 60 is converted into natural speech and is preferablybroadcast through a speaker 28 It should be understood that eachsynthesizer may be connected to a separate speaker or multiple speakersand that in a different embodiment the speech synthesizer 60 and thesound synthesizer 50 may be integrated into a single function, thespeech and sound synthesizer.

AutoRULE may be deployed on location, such as a wellsite, a chemicalplant or refinery, an airport tarmac or a bridge, a storage yard orfacility, a manufacturing facility, such as a pipe mill, a locomotiveand in general in a noisy industrial and/or transportation environment.AutoRULE rarely is deployed in a laboratory where typical sound levels,similar to a bank lobby, may be in the range of 40 db to 50 db whilefactory or industrial sound levels may exceed 80 db. A frequencybandwidth of substantially 300 Hz to 2500 Hz and a dynamic range ofsubstantially 40 db may be adequate for good quality speech with goodquality listenability and intelligibility. Industrial noise may also bepresent in the same frequency range. The notch filters 71 may be“parked” outside of this frequency range or bypassed altogether when thenoise level is acceptable. When a machine, a jet engine, or other devicestarts suddenly, the notch filters 71 would preferably sweep to matchthe predominant noise frequencies. The notch filters 71 may be activatedeither manually or through a fast tracking digital signal processingalgorithm. Narrow notch filters 71 with a substantially 40 db rejectionare known in the art and can thus be readily designed and implemented bythose skilled in the art. Furthermore, it should be understood thatstandard noise cancellation techniques could also be applied to theoutput of the sound synthesizer 50 and the speech synthesizer 60 whenthe speaker 28 comprises a set of earphones such as in a headset.

Language Selection

It should be further understood that different AutoRULE may beprogrammed in different languages and/or with different commands butsubstantially performing the same overall function. The languagecapability of the AutoRLTLE may be configured to meet a wide variety ofneeds. Some examples of language capability, not to be viewed aslimiting, may comprise recognizing speech in one language and respondingin a different language; recognizing a change of language and respondingin the changed language; providing manual language selection, which mayinclude different input and response languages; providing automaticlanguage selection based on pre-programmed instructions; simultaneouslyrecognizing more than one language or simultaneously responding in morethan one language; or any other desired combination therein. It shouldbe understood that the multilanguage capability of the AutoRULE voiceinteraction is feasible because it is limited to a few dozen utterancesas compared to commercial voice recognition systems with vocabularies inexcess of 300,000 words per language.

Operator Identification and Security

Preferably, at least some degree of security and an assurance of safeoperation, for the AutoRULE, is achieved by verifying the voiceprint ofthe operator and/or through facial or irisscan or fingerprintidentification through camera 29 or any other biometric device. Withvoiceprint identification, the likelihood of a false command beingcarried out is minimized or substantially eliminated. It should beappreciated that similar to a fingerprint, an irisscan, or any otherbiometric, which can also be used for equipment security, a voiceprintidentifies the unique characteristics of the operator's voice. Thus, thevoiceprint coupled with passwords will preferably create a substantiallysecure and false command immune operating environment.

It should be further understood that the authorize operator may also beidentified by plugging-in AutoRULE a memory storage device withidentification information or even by a sequence of sounds and ormelodies stored in a small playback device, such as a recorder or anycombination of the above.

Assessment Trace to Sound Conversion

The prior art does not present any solution for the conversion of theassessment signals, including but not limited to inspection signals,also referred to as “assessment traces”, to speech or sound. The presentinvention utilizes psychoacoustic principles and modeling to achievethis conversion and to drive the sound synthesizer 50 with the resultingsound being broadcast through the speaker 28 or a different speaker.Thus, the assessment signals may be listened to alone or in conjunctionwith the AutoRULE comments and are of sufficient amount and quality asto enable the operator to monitor and carry out the entire assessmentprocess from a remote location, away from the AutoRULE console and thetypical readout instruments. Furthermore, the audible feedback isselected to maximize the amount of information without overload orfatigue. This trace-to-sound conversion also addresses the dilemma ofsilence, which may occur when the AutoRULE has nothing to report.Typically, in such a case, the operator is not sure if the AutoRULE issilent due to the lack of features or if it is silent because it stoppedoperating. Furthermore, certain MUI 1 features such as, but not limitedto, collars or welds can be observed visually and the synchronized audioresponse of the AutoRULE adds a degree of security to anyone listening.A wearable graphics display, such as an eyepiece, could serve as theremote display 21 to further enhance the process away from the AutoRULEconsole.

It should be understood that the assessment trace(s) to sound conversionis not similar to an annoying chime indicating that an automobile dooris open, or that there is a message in an answering machine. The timevarying AutoRULE processing results are converted to sound of sufficientamount and quality through psychoacoustic principles and modeling, as toenable the operator to monitor and carry out the entire AutoRULE processfrom a remote location without annoying the operator or resulting inoperator overload or operator “zone-out”. It should further beunderstood that a switch contact closure indicating that an automobiledoor is open or a vending machine bin is empty does not constitute anRUL assessment as it is not different than turning on the lights in aroom. Conversely, a chime may be attached to the light to indicate thatit is on or even a voice synthesizer to say “the light is on”.Similarly, lights may be attached to a doorbell switch closure to assista hearing impaired person, however, none of these devices or actionsconstitute a RUL assessment.

AutoRULE Speech

Text to speech is highly advanced and may be implemented without greatdifficulty. Preferably, when utilizing text to speech, the Auto AutoRULEcan readily recite its status utilizing, but not limited to, suchphrases as: “magnetizer on”; “chart out of paper”, and “low battery”. Itcan recite the progress of the AutoRULE utilizing, but not limited to,such phrases as: “MUA stopped” and “four thousand feet down, sixthousand to go”. It can recite readings utilizing, but not limited to,such phrases as “wall loss”, “ninety six”, “loss of echo”, “unfitmaterial”, “ouch”, or other possible code words to indicate a rejectabledefect. The operator would not even have to look at a watch as simplevoice commands like “time” and “date” would preferably recite theAutoRULE clock and/or calendar utilizing, but not limited to, suchphrases as “ten thirty two am”, or “Monday April eleven”.

However, t should be understood that the primary purpose of the AutoRULEis to relay MUA 9 information to the operator. Therefore, AutoRULE wouldfirst have to decide what information to relay to the operator and therelated utterance structure.

AutoRULE Operation Through Speech

Preferably, the structure and length of AutoRULE utterance would be suchas to conform with the latest findings of speech research and inparticular in the area of speech, meaning and retention. It isanticipated that during the AutoRULE deployment, the operator would bedistracted by other tasks and may not access and process the short termauditory memory in time to extract a meaning. Humans tend to betterretain information at the beginning of an utterance (primacy) and at theend of the utterance (recency) and therefore the AutoRULE speech will bestructured as such. Often, the operator may need to focus and listen toanother crew member, an alarm, a broadcasted message or even anunfamiliar sound and therefore the operator may mute any AutoRULE speechoutput immediately with a button or with the command “mute” and enablethe speech output with the command “speak”.

The “repeat” command may be invoked at any time to repeat an AutoRULEutterance, even when speech is in progress. Occasionally, the “repeat”command may be invoked because the operator failed to understand amessage and therefore, “repeat” actually means “clarify” or “explain”.Merely repeating the exact same message again would probably not resultin better understanding, occasionally due to the brick-wall effect.Preferably, AutoRULE, after the first repeat, would change slightly thestructure of the last utterance although the new utterance may notcontain any new information, a strategy to work around communicationobstacles. Furthermore, subsequent “repeat” commands may invoke the helpmenu to explain the meaning of the particular utterance in greaterdetail.

The operator may remain in communication with the AutoRULE in a varietyof conventional ways. Several examples, which are not intended aslimiting, of possible ways of such communication are: being tethered tothe AutoRULE; being connected to the AutoRULE through a network ofsockets distributed throughout the site including the inspectionhead(s); being connected to the AutoRULE through an optical link(tethered or not); or being connected to the AutoRULE through a radiolink. This frees the operator to move around and focus his/her attentionwherever needed without interfering with the production rate.

It should be appreciated that the present invention may be a small scalespeech recognition system specifically designed to verify the identityof the authorized operator, to recognize commands under adverseconditions, to aid the operator in this interaction, to act according tothe commands in a substantially safe fashion, and to keep the operatorinformed of the actions, the progress, and the status of the AutoRULEprocess.

AutoRULE Sound Recognition

AutoRULE would preferably be deployed in the MUA 9 use site and would beexposed to the site familiar and unfamiliar sounds. For example, afamiliar sound may originate from the rig engine revving-up to trip anOCTG string out of a well. An indication of the MUA 9 speed of travelmay be derived from the rig engine sound. An unfamiliar sound, forexample, would originate from an injector head bearing about to fail. Itshould be noted that not all site sounds fall within the human hearingrange but may certainly fall within the AutoRULE analysis range when theAutoRULE is equipped with appropriate microphone(s) 27. It should alsobe noted that an equipment unexpected failure may affect adversely theMUA 9 RUL, thus training the AutoRULE to the site familiar, and whenpossible unfamiliar sounds, would be advantageous.

As discussed earlier, the notch filters 71 would preferably sweep tomatch the predominant noise frequencies, thus, a noise frequencyspectrum may be derived that may further be processed for recognitionusing standard AutoRULE recognition techniques.

Description of Speech and Sound Interface

FIG. 6 illustrates a block diagram of a preferred sound synthesizer 50,speech synthesizer 60, and speech and sound recognition engine 70. Itshould be understood that these embodiments should not be viewed aslimiting and may be tailored to specific inspection constraints andrequirements.

The sound synthesizer 50 and the speech synthesizer 60 may comprise atunes and notes table 51 and a vocabulary table 61 respectively. Thedigital-to-analog (herein after referred to as “D/A”) converter 52, 62,the reconstruction filter 53, 63, and the variable gain output amplifier54, 69 are in communication with computer 20. The tunes and notes table51 and a vocabulary table 61 may be implemented in a read only memory(ROM) or any other storage device. The computer 20 preferably sequencesthrough the entire address sequence so that the complete digital data ofthe utterance (word, phrase, melody, tune, or sound), properly spaced intime, are converted to an analog signal through the D/A 52, 62. Theanalog signal is then preferably band-limited by the reconstructionfilter 53, 63, amplified by the amplifier 54, 64, and sent to thespeaker 28. Preferably, the computer 20 can vary the bandwidth of thereconstruction filter 53, 63 and adjust the gain of the amplifier 54, 64which may be programmable gain amplifiers 80 as depicted in FIG. 8A. Ina different embodiment, the gain of the amplifier 54, 64 may be adjustedby the operator.

It should be understood that the tunes and notes table 51 and avocabulary table 61 may incorporate a built in sequencer with thecomputer 20 providing the starting address of the utterance (word,phrase, melody, tune, or sound). It should be further understood thatthe sound synthesizer 50 and the speech synthesizer 60 may compriseseparate devices or even be combined into one device, the speech andsound synthesizer, or even be part of a complete sound and video systemsuch devices being commercially available from suppliers such as YAMAHA.It should be understood that an utterance may comprise of a word, ashort phrase and/or sound effects such as melodies, tunes and notes. Avariable length of silence may be part of the utterance, which may ormay not be part of the vocabulary table 61 and/or the tunes and notestable 51 in order to save storage space. Instead, the length of thesilence may be coded in the table 51 and 61 and then be produced througha variable delay routine in computer 20.

Description of the Features Detection Interface

Computer 20 also controls and monitors a plurality of power supplies,sensors and controls 34 that facilitate the AutoRULE process includingbut not limited to MUA 9 identification and safety features. Further,computer 20 monitors/controls the data acquisition system 35 whichpreferably assimilates data from at least one sensor 36 and displays 21Cand stores such data 23. The sensor 36 preferably provides data such as,but not limited to, MUA 9 location (feet of MUA 9 that passed throughthe head 2), penetration rate (speed of MUA 9 moving through the head2), applied torque, rate of rotation (rpm), and coupling torque. Itshould be appreciated that the data to be acquired will vary with thespecific type of MUA 9 and application and thus the same parameters arenot always measured/detected. For example, the length of the MUA 9, suchas a drill pipe joint, may be read from the MUA 9 identificationmarkings or from the identification tag embedded in the MUA 9.Furthermore and in addition to the aforementioned techniques, computer20 may also monitor, through the data acquisition system 35, parametersthat are related to the assessment or utilization of the MUA 9 and/orparameters to facilitate RULE. Such parameters may include, but not belimited to, the MUA 9 pump pressure, external pressure, such as thewellhead pressure, temperature, flow rate, tension, weight, loaddistribution, fluid volume and pump rate and the like. Preferably, theseparameters are measured or acquired through sensors and/or transducersmounted throughout the MUA 9 deployment area, such as a rig. For ease ofunderstanding, these various sensors and transducers are designated withthe numeral 37. The STYLWAN Rig Data Integration System (RDIS-10) is anexample of such a hybrid system combining inspection and dataacquisition. For instance, inserted in the MUA 9 and the head 2 may bestationary or travel along the MUA 9. It should be appreciated that thehead 2 can be applied to the inside as well as the outside of the MUA 9.It should be understood that the head 2, illustrated herein, maycomprise at least one excitation inducer 3 and one or more featuressensors 4 mounted such that the RULE assessment needs of MUA 9 aresubstantially covered. For features acquisition utilizing MFL, theexcitation inducer 3 typically comprises of at least one magnetizingcoil and/or at least one permanent magnet while sensor 4 comprises ofsensors that respond to magnetic field. There is a plethora of sensorsthat respond to the magnetic field such as coils, Hall-probes, magnetodiodes, etc. The computer 20 preferably both programs and controls theexcitation 31 and the head 2 as well as receives features data from thehead sensors 4 through the features sensor interface 33. The head 2,excitation 31, and the features sensor interface 33 may be combinedwithin the same physical housing. In an alternative embodiment, thefeatures sensors 4 may comprise computer capability and memory storageand thus the sensors 4 can be programmed to perform many of the tasks ofthe computer 20 or perform functions in tandem with the computer 20. Itshould be also understood that the application of the excitation 31 andthe assessment of the MUA 9 may be delayed such as AutoRULE utilizingfar-field or the residual magnetic field whereby the MUA 9 is magnetizedand it is scanned at a later time, thus the excitation inducer 3 and thefeatures sensor 4 may be mounted in different physical housings. Itshould be further understood, that in such configuration, the excitationinducer 3 may be applied on the inside or on the outside of MUA 9 whilethe inspection sensor 4 may be applied on the same side or on theopposite side of the excitation inducer 3. It should be furtherunderstood that either or both the excitation inducer such as removingany coating or cutting up the MUI 1 is beyond the scope ofnon-destructive inspection. Detailed signal analysis can extract thepertinent information from the NDI signals. Preferably, such detailedsignal analysis would utilize signals that are continuously related inform, kind, space, and time.

AutoRULE Retrofit to 1D-NDI Equipment

As discussed earlier, it is desirable to provide means to retrofitAutoRULE to the hundreds of 1D-EMI units deployed worldwide. The analogsignals from 1D-NDI or two-dimensional sensors are decomposed infrequency. This frequency decomposition can take place in continuous ordiscrete form. In the continuous form the signals are decomposed througha bank of analog frequency filters and they are then digitized by thecomputer 20. In the discrete form the signals are digitized by thecomputer 20 and they are then decomposed through a bank of digitalfrequency filters or mathematical transforms.

The list of 1D-NDI retrofit candidates includes, but is certainly notlimited to, the OCTG inspection units described in U.S. Pat. No.2,685,672, No. 2,881,386, No. 5,671,155, No. 5,914,596 and No.6,580,268; the pipeline pigs described in U.S. Pat. No. 3,225,293, No.3,238,448 and No. 6,847,207 and the rail inspection systems described inU.S. Pat. No. 2,317,721, No. 5,970,438 and No. 6,594,591 and derived orsimilar units. The simplest retrofit would store the sensor informationin a memory or transmit the sensor information through a communicationlink and the AutoRULE would post-process the data. The retrofit mayconsist of three-dimensional sensors and signal processing or frequencydecomposition and signal processing as described herein below.

The speech and sound recognition engine 70, may comprise ananalog-to-digital (herein after referred to as “A/D”) converter 73, aspectral analyzer 74, and the voice and sound templates table 75 whichmay be implemented in a read only memory (ROM) or any other storagedevice. The description of the sequence of software steps (math,processing, etc.) is well known in the art, such as can be found inTexas Instruments applications, and will not be described in detailherein. An exemplary hardware device is the YAMAHA part number4MF743A40, which provides most of the building blocks for the entiresystem.

Voiceprint speaker verification is preferably carried out using a smalltemplate, of a few critical commands, and would preferably be a separatesection of the templates table 75. Different speakers may implementdifferent commands, all performing the same overall function. Forexample “start now” and “let's go” may be commands that carry out thesame function, but are assigned to different speakers in order toenhance the speaker recognition success and improve security. Asdiscussed herein above, code words can be used as commands. The commandswould preferably be chosen to be multi-syllabic to reduce the likelihoodof false triggers. Commands with 3 to 5 syllables are preferred but arenot required. Further reduction of false triggers can be accomplished bya dual sequence of commands, such as “AutoRULE” and upon a response fromAutoRULE, such as “ready”, followed by the actual command such as“Start” issued within a preset time interval. It should be understoodthat command pairs may or may not share trigger commands. Hardwaretrigger, such as a switch closure, followed by a speech command will bemost effective in reducing false triggers.

computer 20 may monitor, log and evaluate the overall drillingperformance and its impact on the MUA 9 by measuring the powerconsumption of the drilling process, the string weight, weight on bit,applied torque, penetration rate and other related parameters. Suchinformation, an indication of the strata and the efficiency of thedrilling process, may be processed and used as a measure to furtherevaluate the MUA 9 imperfections and its FFS and RUL.

It should be understood that sensors, measuring devices and/or a dataacquisition system may already be installed in the MUA 9 deploymentarea, such as a drilling rig, measuring at least some of theaforementioned parameters, which may be available to AutoRULE throughstorage devices and/or through a communication link 26 as real time dataand/or as historical data. It should be appreciated that the RDIS-10uses the extraction matrix and multidimensional sensors 4. When however,the multidimensional sensors and extraction matrix are replaced with adifferent sensor interface and a bank of frequency filters, as describedherein below, the RDIS-10 will substantially work as described hereinbelow utilizing the frequency derived flaw spectrum.

Regardless of the specific technique utilized, the AutoRULE device willpreferably scan the material after each use, fuse the features data withrelevant material use parameters, and automatically determine the MUA 9status. Thus, a function of the features detection interface 30 is togenerate and induce excitation 31 into the MUA 9 and detect theresponse, of the MUA 9, to the excitation 31. It should be understoodthat computer 20 may first apply an excitation bias to the MUA 9 priorto the evaluation of MUA 9. The excitation bias preferably places MUA 9in a known state prior to the evaluation. Preferably, at least oneassessment head 2 is mounted on or 3 and the features sensor 4 may beapplied on both the inside and on the outside of MUA 9 so that theassessment needs of MUA 9 are substantially covered.

Sensor Signal Processing

Preferably, the head 2 relates time-varying continuous (analog) signals,such as, but not limited to, echo, reluctance, resistance, impedance,absorption, attenuation, or physical parameters that may or may notrepresent a feature of the MUA 9. For features acquisition utilizingMFL, head 2 relates reluctance signals in an analog form. The processingof Eddy-Current amplitude and phase would also result in similar analogsignal. Features generally comprise all received signals and may includeMUA 9 design features such as tapers, imperfections, major and minordefects or other MUA 9 conditions such as surface roughness, hardnesschanges, composition changes, scale, dirt, and the like. Signals fromthree-dimensional sensors 4 are processed by the extraction matrix, thatwas published in 1994 and it is beyond the scope of this patent. Theexemplary RDIS-10 uses the extraction matrix to decompose the converteddigital signals into relevant features.

Typically, those in the 1D-NDI art have always relied on both aninspector and a manual verification crew for the interpretation of theinspection signals and any subsequent disposition of the MUI 1. However,based on extensive strength-of-materials knowledge, it is well knownthat the severity of an MUI 1 imperfection is a function of itsgeometry, its location, and the applied loads. It is also well known, inthe art, that this information cannot be readily obtained by averification crew when the imperfections in question are locatedunderneath coating, in the near subsurface, in the mid wall, or in theinternal surface of the MUI 1. Any destructive action,

Frequency Decomposition with Analog Filters

FIG. 7 illustrates a block-diagram of the addition to the exemplaryRDIS-10 imperfection sensor interface 33, illustrated as preprocessor32, and the filter arrangement to decompose the inspection signalsfrequency spectrum and extract relevant features in an analog format.The features extraction of the present invention is accomplished througha filter bank comprising of a low-pass filter 90 and a number ofband-pass filters 100 through 160N. There is no limit on the number ofband-pass filters that may be used, however six to eight filters areadequate for most applications thus dividing the sensor frequencyspectrum into seven to nine features, the exact number depending on thespecific application. For a scanning speed of 60 feet/minute a typicalalignment time shift (also known as time delay) is 42 milliseconds and atypical nine filter sequence comprises one 12 Hz low-pass filter 90 andeight band-pass filters 100 through 100N with center frequency(bandwidth) of 15 Hz (6 Hz), 25 Hz (10 Hz), 35 Hz (15 Hz), 50 HZ(21 Hz),70 Hz(30 Hz), 100 Hz(42 Hz), 140 Hz(58 Hz) and 200 Hz(82 Hz). Theattenuation of the filters depends on the resolution of theanalog-to-digital converter and the processing with 40 to 60 decibelsbeen sufficient for common applications.

The passband ripple is another important filter consideration. In thepast, the 1D-EMI industry has mostly used Butterworth (also known asmaximally-flat) filters. These are compromise filters with a 3 dbpassband variation. For typical 1D-NDI applications, better performanceis achieved with Chebyshev or Elliptic filters. For example, a 0.5 dbChebyshev filter has less passband variation and sharper rolloff, thusresulting in a lower order filter than an equivalent Butterworth. Theabove specifications (filter type, center frequency, bandwidth andattenuation) are sufficient to design the filters without additionalexperimentation. Filter design software, some available free of charge,is also available from multiple component vendors such as, MicroChip,Linear Technology, and many others.

Preferably, the computer 20 may read and gather relevant sensor 4information from the sensor 4 onboard memory and may write newinformation into the sensor 4 onboard memory. It should be understoodthat the sensor 4 relevant information may also be stored in otherstorage media, such as hard disks, floppy disks, compact discs, magnetictapes, DVDs, memory, and other storage devices that computer 20 mayaccess. The sensor 4 analog signal 4A is amplified by a programmablegain amplifier (herein after referred to as “PGA”) 80. This Gain of thePGA 80 is controlled by the computer 20. FIG. 8A through 8D illustrate aPGA 80 and its design equations for clarity. PGAs are well known in theart and multiple designs can be found throughout the literature. PGAintegrated circuits are also commercially available from such vendors asAnalog Devices, Linear Technology, Maxim, National Semiconductors, TexasInstruments, and many others. In its simplest form a PGA comprises adifferential amplifier 851 with a variable resistor 83 inserted in itsfeedback loop. Preferably, the variable resistor 83 is a digitallycontrolled potentiometer such as the ones offered by XICOR. Computer 20may vary the variable resistor 83 value thus adjusting the gain of thePGA 80. The PGA 80 gain adjustment is primarily controlled by the sensor4 information, the instantaneous scanning speed derived by the computer20 from sensor 36 and the specific MUI 1. The output of PGA 80 isconnected to a filter bank in order to decompose the inspection signalsfrequency spectrum and extract relevant features.

The low frequency components are extracted by the low-pass filter 90. Itshould be understood that the term low-frequency features are not inabsolute terms is but in relative terms to the scanning speed.Therefore, the cutoff frequency of the low-pass filter 90, denoted as Fcin FIGS. 9B and 9C, may be set to 5 Hz for one scanning speed and to 50Hz for a higher scanning speed. The exact cutoff frequency of thelow-pass filter 90 depends on the sensor information 4, theinstantaneous scanning speed derived by the computer 20 from sensor 36,and the specific MUI 1. FIGS. 9A, 9B and 9C illustrate a programmable3^(rd) order low-pass analog filter and its design equations forclarity. Low-pass filters are well known in the art and their design canbe found throughout the literature. Filter design software, someavailable free of charge, is also available from multiple componentvendors such as, MicroChip, Linear Technology, and many others. Thelow-pass filter of FIG. 9A consists of two sections. A 1^(st) orderfilter comprising of resistor 91 and capacitor 92 cascaded with a 2^(nd)order low-pass analog filter. It should be understood that all otherfilter orders can be obtained by cascading additional filter sections.Preferably, the variable resistors 91 and 93 are digitally controlledpotentiometers such as the ones offered by XICOR and a fixed resistorvalue (not shown) similar to the FIG. 8A network 83 and 84. Computer 20may vary the variable resistor 91 and 93 value thus adjusting the cutofffrequency of the low-pass filter.

All other frequency components of the sensor signal 4 are extracted bythe band-pass filters 100 through 100N. Again, it should be understoodthat the frequency bands are not stated in absolute terms but inrelative terms to the scanning speed. Therefore, the center frequency ofa band-pass filter 100 may be set to 40 Hz for one scanning speed and to200 Hz for a higher scanning speed. The exact center frequency of theband-pass filters 100 through 100N depends on the sensor information 4,the instantaneous scanning speed derived by the computer 20 from sensor36 and the specific MUI 1. FIG. 10A illustrates a programmable 3^(rd)order band-pass filter that is made up from a low-pass filter 90cascaded with a 3^(rd) order high-pass filter. The 3^(rd) orderhigh-pass filter and its design equations are shown for clarity.High-pass filters are well known in the art and its design can be foundthroughout the literature. Filter design software, some available freeof charge, is also available from multiple component vendors such as,MicroChip, Linear Technology, and many others. The high-pass filter ofFIG. 10A includes two sections. A 1^(st) order filter comprising ofcapacitor 101 and resistor 102 cascaded with a 2^(nd) order high-passfilter. It should be understood that all other filter orders can beobtained by cascading additional filter sections. Preferably, thevariable resistors 102 and 104 are digitally controlled potentiometerssuch as the ones offered by XICOR and a fixed resistor value (not shown)similar to the FIG. 8A network 83 and 84. Computer 20 may vary thevariable resistor 102 and 104 value thus adjusting the cutoff frequencyof the high-pass filter. It should be further understood that thisband-pass filter configuration allows for individual adjustment of boththe leading and trailing transition bands. Other band-pass filterconfigurations can also be found throughout the literature.

Frequency Decomposition in the Digital Domain

The features extraction filter bank that was described above usinganalog filters may also be realized with switched capacitor filtersand/or digital filters and/or mathematical transforms or any combinationthereof. Switched capacitor filters may be substituted for the analogfilters 90 and 100 through 100N with the computer 20 varying the clockfrequency to program the resulting switched capacitor filter bank.

It should be understood that no modification to the front end of theinspection sensor interface 33 (i.e. no preprocessor 32 as describedhereinabove) of the exemplary RDIS-10 is required in order to implementthe present invention using digital filters and/or mathematicaltransforms as the exemplary RDIS-10 is designed for digital domainoperation.

The sensor signal therefore, is converted to digital format and theanalog filters described above may be converted to their digitalcounterpart using bilinear transform which is well known to the art andwell publicized resulting in Infinite Impulse Response digital filters(known to the art as IIR filters) and is illustrated in FIGS. 11A, 11Band 11C. The block diagram of FIG. 7 may then be used to derive theflowchart of the digital signal processing form of the presentinvention. In another implementation, digital filters may be designedusing direct synthesis techniques that are also well known to the artand well publicized. Finite Impulse Response digital filters (known tothe art as FIR filters) may also be employed at the expense of computingpower. FIR implementations, such as Kaiser, Hamming, Hanning etc, arealso well known to the art and well publicized.

There are many mathematical transforms that are well known and wellpublicized. However, not all are useful for features extraction for thetransient NDI signals. The NDI industry in the past has proposed the useof Fourier Transform or its Fast Fourier Transform (FFT) implementation,a misapplication for the brief transient NDI imperfection signals.Fourier Transform, in all of its implementations, is useful to analyzelong periodic signals (long waves). Furthermore, the Fourier Transformprovides information in the frequency domain and none in the time domainwhich is essential for the analysis of NDI signals. This drawback of theFourier Transform was noted by the French Academy and in particular byJ. L. Lagrange who objected to the Fourier Transform trigonometricseries because it could not represent signals with corners such as theones often encountered in NDI. Subsequently, the Academy refused topublish the Fourier paper. In order to overcome the drawbacks of theFourier Transform, alternatives were developed over the years, notablythe Short Time Fourier Transform (commonly referred to as STFT),wavelets and coiflets all of which are well known to the art and wellpublicized. The main disadvantages of the transforms are their fixedresolution and their demand for higher computer power.

The STFT offers uniform time and frequency resolution throughout theentire time-frequency domain using a fixed window size, which results inits main drawback. A small window blind the STFT to low frequencieswhile a large window blinds the STFT to brief signal changes mostlyassociated with use induced MUI 1 imperfections.

Wavelets (short waves) are better tuned to the needs of NDI. Waveletsvary the width of the window thus offer better time resolution for thehigher frequencies that are typically associated with use induced MUI 1imperfections. Wavelets are typically implemented using filter banks andthey are also well known in the art and well publicized. FIGS. 12A, 12Band 12C illustrate the implementation of the discrete wavelet transformdecomposition using filter banks and down sampling.

Sensor Signal Normalization

Referring back to FIG. 7, the bank of PGAs 80A through 80N follows thefrequency decomposition filter bank. The frequency response of theinspection sensors 4 is typically non-linear. The response of theinspection sensor 4 to the same MUI 1 feature would then vary dependingon the scanning speed and level of excitation which is continuouslymonitored by computer 20. The sensor 4 response to different scanningspeeds, in the unique setting of the inspection head 2 under varyingexcitation 31 levels, can be characterized. This is accomplished byscanning MUI 1 samples with test imperfections at different speeds anddifferent levels of excitation while recording the sensor 4 signals.Preferably, these sensor characterization tests would be repeatedmultiple times so that a sufficiently large database for the specificsensor is obtained. The characteristics of the particular sensor 4 arethen preferably stored in the memory onboard the sensor 4. Computer 20reads the sensor 4 characteristics and adjusts the bank of PGAs 80Athrough 80N to normalize the sensor signal. This band signal amplitudecompensation along with the capability of computer 20 to adjust both thepass-band width and the transition slopes of the filters allows computer20 to fully normalize the imperfection signals.

The outputs of the bank of PGAs 80A through 80N are then converted todigital form through an analog-to-digital converter of sufficientresolution, typically 10 to 14 bits, and speed which is defined by thenumber of channels and maximum scanning speed.

AutoRULE Processing

AutoRULE processing operates upon the flaw spectrum that was derivedfrom signals, such as, but not limited to, echo, reluctance, resistance,impedance, absorption, attenuation, sound or physical parametersacquired through one-dimensional or multi-dimensional sensors. Theprocessing of Eddy-Current amplitude and phase, for example, may also beutilized to derive the flaw spectrum as well as frequency decompositionas described herein above. Regardless of the signal origin or thefrequency decomposition method used, the frequency components of thesignals then become the flaw spectrum for use by the AutoRULE in amanner illustrated by element 21A in FIG. 13. It should be understoodthat computer 20 can manipulate and present the signals in any desirableformat. It should be further understood that the signals ofgeometrically offset sensors, such as the ones shown in FIG. 7 of U.S.Pat. No. 2,881,386, are aligned by computer 20 through time shifting(time delay) primarily controlled by the scanning speed preferablyderived from sensor 36. This may comprise memory, a bucket-brigade, orany combination of the above. Variable length analog delay lines mayalso be deployed, the delay length controlled primarily by the scanningspeed. It should be understood that sensor 36 may comprise a number ofsensors distributed along the length of MUI 1 for direct measurement orcoupled to MUI 1 transport components, such as the lifting cable, or acombination thereof.

It should be understood that the exemplary RDIS-10 extraction matrix iscompiled through a software program, that was published in 1994 and itis beyond the scope of this patent, and decomposes the converted digitalsignals into relevant features. The extraction matrix may be adjusted todecompose the signals into as few as two (2) features, such as, but notlimited to, the 1D-NDI presentation of wall and flaw. It should beunderstood that no theoretical decomposition upper limit exists,however, fifty (50) to two hundred (200) features are practical. Theselection of the identifier equations, further described herein below,typically sets the number of features. In the exemplary RDIS-10, thedecomposed signals, regardless of their origin, are known as the flawspectrum 6 (see FIG. 2C).

Feature Recognition

Humans are highly adept in recognizing patterns, such as facial featuresor the flaw spectrum 6 and readily correlating any pertinentinformation. Therefore, it is easy for the inspector to draw conclusionsabout the MUI 1 by examining the flaw spectrum 6, as further illustratedin FIGS. 15A through 15E. During the inspection, the inspector furtherincorporates his/her knowledge about the MUI 1 present status, his/herobservations, as well as the results of previous inspections. Thesuccess of this inspection strategy of course, solely depends on howwell the inspector understands the flaw spectrum 6 data and the nuancesit may encompass.

Computers can run numerical calculations rapidly but have no inherentpattern recognition or correlation abilities. Thus, a program has beendeveloped that preferably derives at least one mathematical procedure toenable the computer 20 to automatically recognize the patterns andnuances encompassed in decomposed inspection and/or sound data streamssuch as presented in the flaw spectrum 6. The detailed mathematicalprocedures are described hereinbelow and enable one skilled in the artto implement the AutoRULE described herein without undueexperimentation.

FIG. 13 illustrates a block diagram of an AutoRULE data processingsequence that allows the creation of a software flowchart and thetranslation of the practice to a computer program. For stand-aloneoperation, the AutoRULE must be optimal in regard to the RULE criteriaand application limitations, commonly defined by approximations andprobabilities which are referred to herein as constraints. It should beunderstood therefore, that the AutoRULE state variables must be tunedfor optimal performance under different constrains depending on the MUA9 and its application. The fundamental operation of the AutoRULE isperformed by the identifier equations which preferably capture theoptimal mutual features in accordance to the constraints. It should beunderstood that a number of identifier equations may be paralleledand/or cascaded, each one utilizing a different set of optimal mutualfeatures. Furthermore, it should be understood that the processing ofthe identifier equations may be carried out by a single computer 20 orby different computers in a cluster without effecting the overallresult.

The first stage identifier equations, with elements denoted as a_(jk)112, 114, use for input N features 111 mostly derived from the flawspectrum 21A. Additional features may be provided by fixed valuesreferred to herein as bias 113, 123, 133. Bias may be a single constantor a sequence of constants that may be controlled, but not limited, bytime or by the MUA 9 length. Backwards chaining 119 limits irrelevantprocessing and enhances stability while forward chaining 139 propagatesfeatures to later stages or it may inform computer 20 that an MUA 9condition has been determined and no further analysis is required. Itshould be further understood that both forward and backward chaining maybe direct, through memory, through a bucket-brigade, or any combinationof the above. It should be further understood that all or any subsystemof the AutoRULE may be implemented as a casual system or as a non-casualsystem. In a casual implementation only past and present features 111are utilized. In a non-casual implementation, features 111 are utilizedthrough memory, through a bucket-brigade, or any combination of theabove thus allowing for the use of future values of the features 111.Future values of the features 111 may be used directly or indirectly assignal masks and may be propagated through the forward chaining 139.Utilization of future values of features 111 increases the AutoRULEstability and reduces the probability of a conflict In Equations 1-3,shown below, such features are denoted as Xa. Based on the constrains,the identifier equations reduce the features 111 and bias 113 toidentifiers 115, 116 denoted as Ya of the form:

$\begin{matrix}{{Ya}_{ij} = {M{\sum\limits_{k = 1}^{N}\; {a_{ik}{Xa}_{kj}}}}} & ( {{Equation}\mspace{14mu} 1} )\end{matrix}$

The identifiers Ya 115, 116 can be fed back through the backwardschaining 119, can be used directly through the forward chaining 139, canbe used as variables to equations or as features 121, 131 in followingstages or in their most practical form, as indexes to tables (arrays)which is shown in Equation 2 for clarity.

$\begin{matrix}{{Ya}_{ij} = {M\lbrack {1 + ^{- {\sum\limits_{k = 1}^{N}\; {a_{ik}{Xa}_{kj}}}}} \rbrack}^{- 1}} & ( {{Equation}\mspace{14mu} 2} )\end{matrix}$

where T is a Look-up Table or Array.

Another useful identifier form is shown in Equation 3.

$\begin{matrix}{{Ya}_{ij} = T_{({M{\sum\limits_{k = 1}^{N}\; {a_{ik}{Xa}_{kj}}}})}} & ( {{Equation}\mspace{14mu} 3} )\end{matrix}$

where M is a scaling constant or function.

It should be understood that each stage may comprise multiple identifierequations utilizing equations 1, 2, or 3. There is no theoretical upperlimit for the number of identifiers calculated, however, five (5) to ten(10) identifiers are practical.

Some of the identifiers Ya 115, 116 may be sufficient to define thedisposition of the MUI 1 alone and thus propagate to the output stage139 while others may become features for the second stage 120 ofidentifier equations along with features 121 pertinent to the Yaidentifiers, all denoted as Xb. It should be appreciated that in theexemplary STYLWAN RDIS-10, depending on the constrains, those featurescan be obtained from the operator interface, from the computer 20memory, from the camera 29, or by connecting directly to the STYLWANRDIS-10 Data Acquisition System transmitters that measure variousparameters illustrated FIG. 41 (21C). Examples of such transmittersinclude the OCI-5000 series manufactured by OLYMPIC CONTROLS, Inc,Stafford, Tex., USA, such as transmitters that measure pressure(OCI-5200 series), temperature (OCI-5300 series), speed and position(OCI-5400 series), weight (OCI-5200H series), fluid level (OCI-5200Lseries), flow (OCI-5600 series), dimensions (OCI-5400D series), ACparameters (OCI-5400 series), DC parameters (OCI-5800 series), as wellas other desired parameters. The second stage 120 identifier equations,with elements denoted as b_(lm), produces identifiers 125,126 denoted asYb of similar form as the Ya identifiers 115, 116.

Again, some of the identifiers Yb may be sufficient to define thedisposition of the MUI 1 alone and thus propagate to the output stage139 while others may become features for the third stage 130 identifierequations along with features pertinent to the Yb identifiers, alldenoted as Xc. For the RDIS-10, depending on the constrains, thosefeatures can be obtained from data or functions entered by the operator138, stored in historical data 137, or other predetermined sources (notillustrated). It should be understood that this process may repeat untilan acceptable solution to the constrains is obtained, however, threestages are typically adequate for the exemplary STYLWAN RDIS-10. Itshould further be understood that each stage 110, 120 and 130 maycomprise multiple internal stages.

Determination of Coefficients

For the determination of the a_(ik) coefficients, the tuning of theidentifier equations, a set of flaw spectrums 6 of known similarimperfections that are pertinent to a current inspection application arerequired. These data sets, of flaw spectrums 6, are referred to hereinas baseline spectrums. Preferably, all the a_(ik) coefficients areinitially set equal. It should be understood that because this is aniterative process the initial values of the a_(ik) coefficients couldalso be set by a random number generator, by an educated guess, or byother means for value setting.

Since the baseline spectrums are well known, typically comprising datataken for similar imperfections, the performance measure and theconstrains are clearly evident and the coefficients solution istherefore objective, although the selection of the imperfections may besubjective. By altering the coefficient values through an iterativeprocess while monitoring the output error an acceptable solution wouldbe obtained.

There are multiple well-known techniques to minimize the error and mostof these techniques are well adept for computer use. It should beappreciated that for the AutoRULE limited number of features atrial-and-error brute force solution is feasible with the availablecomputer power. It should be further expected that different solutionswould be obtained for every starting set of coefficients. Each solutionis then evaluated across a variety of validation spectrum as eachsolution has its own unique characteristics. It is imperative,therefore, that an extensive library of both baseline spectrums andvalidation spectrums must be available for this evaluation. It should befurther understood that the baseline spectrums cannot be used asvalidation spectrums and visa versa. Furthermore, it should beunderstood that more than one solution may be retained and used forredundancy, conflict resolution, and system stability. Still further inapplications of the AutoRULE, the terms “acceptable” or “good enough”are terms of art to indicate that, in a computational manner, thecomputer has completed an adequate number of iterations to compile ananswer/solution with a high probability of accuracy.

Once a set or sets of coefficients are obtained, the number of non-zerocoefficients is preferably minimized in order to improve computationalefficiency. This is important because each identifier equation is just asubsystem and even minor inefficiencies at the subsystem level couldsignificantly affect the overall system real time performance. Multipletechniques can be used to minimize the number of non-zero coefficients.A hard threshold would set all coefficients below a predetermined setpoint to zero (0). Computers typically have a calculation quota, so aquota threshold would set to zero a sufficient number of lower valuecoefficients to meet the calculation quota. A soft threshold wouldsubtract a non-zero constant from all coefficients and replace thenegative values with zero (0). Since an error measure exists, the newset of coefficients can be evaluated, the identifier equations can betuned again and the process could repeat until the admissible identifierequation is determined. It is preferred that multiple admissibleidentifier equations are determined for further use. It should beappreciated that although the preference for multiple admissibleidentifiers may appear to complicate potential resolutions, the use ofcomputer power makes a large number of iterations feasible.

For the assessment of materials, an acceptable solution would alwayscontain statistics based on false-positive and false-negative ratios. Afalse-positive classification rejects fit material while afalse-negative classification accepts unfit material. Using more thanone identifier equation lowers the false ratios more than thefine-tuning of a single identifier equation. It should be understoodthat this process theoretically provides an infinite number ofsolutions, as an exact formulation of the inspection problem is elusiveand always based on constrains. Furthermore, for a solution that can beobtained with a set of coefficients, yet another solution that meets theperformance measure may also be obtained by slightly adjusting some ofthe coefficients. However, within the first three to five properiterations the useful solutions become obvious and gains from additionaliterations are mostly insignificant and hard to justify.

Once all of the Stage-I 110 admissible identifier equations have beendetermined, their identifiers become features in Stage-II 120 along withthe additional features 121, bias 123, and forward and backwardschaining 129. The starting set of baseline spectrums is then processedthrough the admissible identifier equations and the results are used totune the Stage-II 120 identifier equations in a substantially identicalprocess as the one described above for the Stage-I 110. The processrepeats for the Stage-III 130 identifier equations and any other stages(not illustrated) that may be desired or necessary until all theadmissible subsystems are determined and the overall system design iscompleted. It should be appreciated that in practice, preferably onlytwo to five stages will be necessary to obtain required results. Whenthe final coefficients for all of the equations are established, theoverall system performance may be improved by further simplifying theequations using standard mathematical techniques.

A previous assessment with the same equipment provides the besthistorical data 137. The previous RULE assessment, denoted as Ys⁽⁻¹⁾, isideally suited for use as a feature 131 in the current inspection as itwas derived from substantially the same constrains. Furthermore, morethan one previous RULE assessment 137 may be utilized. Features 131 maybe backwards chained 129, 119. Multiple historical values may allow forpredictions of the future state of the material and/or the establishmentof a service and maintenance plan.

Determination of Bias

In conventional inspection systems, previous state data, that wasderived through a different means under different constrains, could notnecessarily be used directly or used at all. If utilized, the data wouldmore likely have to be translated to fit the constrains of the currentapplication. It should be appreciated that such a task may be verytedious and provide comparatively little payoff. For example, there isno known process to translate an X-Ray film into MFL pertinent data.However, the AutoRULE system described herein allows for the use of suchdata in a simple and direct form. In the X-Ray example, the opinion ofan X-Ray specialist may be solicited regarding the previous state of thematerial. The specialist may grade the previous state of the material inthe range of one (1) to ten (10), with one (1) meaning undamaged newmaterial. The X-Ray specialist opinion is an example of bias 113, 123,133. Bias 113, 123, 133 may not necessarily be derived in its entiretyfrom the same source nor be fixed throughout the length of the material.For example, information from X-Rays may be used to establish theprevious material status for the first 2,000 feet of an 11,000 footcoiled tubing string. Running-feet may be used to establish the previousmaterial status for the remainder of the string except the 6,000 foot to8,000 foot range where OD corrosion has been observed by the inspector138. From the available information, the previous material status forthis string (bias per 1,000 feet') may look like [2, 2, 4, 4, 4, 4, 7,7, 4, 4, 4] based on length. Other constrains though may impose a hardthreshold to reduce the bias into a single value, namely [7], for theentire string.

An example of a bias array would be a marine drilling riser string whereeach riser joint is assigned a bias based on its age, historical use,Kips, vortex induced vibration, operation in loop currents, visualinspection, and the like. The bias for a single riser joint may thenlook like [1, 1, 3, 1, 2, 2]. Identifier equations may also be used toreduce the bias array into a bias value or a threshold may reduce thebias into a single value.

FFS Assessment and RULE

AutoRULE provides means to move the FFS and RUL process from thelaboratory or the engineering department to the field and apply FFS andRUL to the in-service material using actual as-is field data.Furthermore, it should be understood that AutoRULE may be utilized togather actual field data to create FFS and RUL methods, charts, tablesand formulas or to verify the validity of proposed or existing FFS andRUL methods, charts, tables and formulas. It should be understood thatFFS utilizes information to derive the MUA 9 present status and RULE isusing knowledge and data to project the future status of MUA 9 underdeployment. The RULE higher inherent uncertainty can be minimized byfrequent AutoRULE scans. Frequent data points verify the correctness ofthe original formulas, data and constraints. Furthermore, frequentAutoRULE scans shorten the look-forward time interval simplifying theAutoRULE significantly. For example, if drill pipe is scanned every sixmonths, the look-forward interval is six months and multiple trips. Onthe other hand, if drill pipe is scanned on every trip, the look forwardinterval may be a few days and a single trip resulting in a much simplerAutoRULE. A simpler AutoRULE would certainly be less expensive and itsRULE by far more reliable, therefore encouraging more frequent use.Furthermore, more frequent AutoRULE deployment would monitor and utilizeactual data from related parameters 21C that would not be availableotherwise.

It should also be understood that RULE processing differs if the MUA 9is a serial or parallel structure and if the damage mechanisms act inseries or in parallel. For example, a drill string, while drilling, is aserial structure that will fail as soon as one of the drill pipe jointsfail. The drilling process will fail also. Therefore, at the end of theAutoRULE scan, AutoRULE should also evaluate the FFS and estimate a RULfor the drill string as a single MUA 9 (a structure). On the other hand,when the exact same drill pipe is on a rack, it is a parallel MUA 9.Failure of any drill pipe joint, only impacts the particular joint.Failure of more than one drill pipe joint may prevent the drillingprocess from starting (not enough drill pipe), however, there aredifferent risks and costs associated with the two failures,failure-to-start and failure-while-drilling.

At first glance it may appear that an FFS assessment and RULE for thedrill string as a single MUA 9 (a structure) could also be obtained forexample, through a formula that operated upon the individual FFS andRULE of each drill pipe joint on the rack. One should keep in mind thatthe position of each drill pipe joint in the drilling string affects itsFFS and RULE significantly as the entire string does not endure the sameloads. The entire string RULE is shown in element 196 of FIG. 19B (andFFS is similarly shown in the corresponding FFS baragraph).

AutoRULE may utilize industry standard or custom FFS and RUL methods,charts and formulas, utilize original design data and criteria, materialtest reports, deployment history, prior inspection records, prior FFSand RUL records, repair and/or alteration records along with FFSassessment and RULE techniques and/or formulas and/or data sets,imperfection allowance rules and/or formulas and/or data sets,acceptance criteria, remediation options and/or formulas and/or datasets. AutoRULE makes provisions to accept such information/data eitheras a mathematical or logical (crisp or fuzzy) formula, as a sequence ofdata, such as bias, or even as a single constant.

Typically and in addition to FDDim, AutoRULE would evaluate materialutilizing: a) absolute values, such as actual wall thickness; b)parameter ratios or remaining ratios, such as (strength of damagedmaterial)/(strength of undamaged material); c) coverage ratios, such as(pitted area surface)/(material surface) and d) rates of change, such asfeature morphology, size, density, coverage and any combination thereof.Preferably, AutoRULE would also utilize a measure of the damagemechanism time-dependency. AutoRULE would apply FFS assessment and RULEfor each feature and/or damage mechanism and then fuse the results ofeach FFS assessment and RUL estimation to determine the status of thematerial. It should be understood that the combination of FDDim with theother AutoRULE measured/calculated values would result in amultidimensional pointer sufficient to select the material status from amultidimensional group of tables or charts or to solve a system ofequations. For example, remaining wall thickness RULE tables and chartsmay be indexed on the (maximum) operating pressure and temperature. Bycontinuously monitoring the actual operating pressure and temperature,AutoRULE would then select the appropriate FFS assessment and RULE pathand alert the operator when operating pressure and temperature exceed alimit, affecting the material FFS and RUL. In a different embodiment,AutoRULE could establish communication with a pressure and temperaturemonitor using communication port 26 and download the pressure andtemperature historical data from the monitor memory. Such data may alsobe available in a storage device 23.

AutoRULE may also utilize each damage mechanism time-dependency toestimate the material RUL. Since AutoRULE would preferably be monitoringother controlling parameters, such as pressure, temperature, deflectionetc, it should be understood that AutoRULE (prognosis and/orpredictions) would be based on measured parameters instead of estimatedparameters. It should be further understood that even small changes inthe application and/or environment might result in significant RULchanges. Therefore, AutoRULE results would be bound by the monitoredstability of the controlling parameters. This is a very importantelement when gathering field data to establish material/application FFSand RUL or when verifying proposed FFS and RUL.

AutoRULE preferably may a) scan the MUA 9 after each use; b) identifythe features of MUA 9; c) quantify the features of MUA 9; d) assess theimpact of the features upon the MUA 9, e) estimate the FFS and RUL ofMUA 9 under the constraints of the application and f) (optional)generate and export a file for use by an FEA engine. It should also beapparent that AutoRULE deployment and utilization should be economicallysound.

FIG. 14 illustrates a typical RULE flaw chart. As mentioned earlier,AutoRULE utilizes primarily as-built or as-is data 110, 120 and 130. Thefirst AutoRULE step is to separate design features and imperfections140. When design data is available, AutoRULE also monitors compliancewith the design data 142. Typically, once each imperfection has beenidentified, its severity 141A may be established by applying stressconcentration correction factors and neighborhood information correctionfactors. The imperfection identification may also be utilized toestablish the MUA 9 degradation mechanism 141B. An FFS for the featureis then calculated 141C. When multiple degradation mechanisms areidentified, their interaction (in series or in parallel) affecting theMUA 9 would also modify the AutoRULE processing path.

For each feature, including imperfections, the acceptance/rejectioncriteria are then applied 142. When the degradation mechanism is known,preventive action 146 may reduce/prevent further MUA 9 deterioration,such as relocating the OCTG in a string, repairing damaged protectivecoating or using corrosion inhibitors. Conversely, comparison withprevious RULE records 137 may measure the effectiveness of any priorpreventive action. Occasionally, re-rating 148 the MUA 9 early on mayresult in an extended useful life in service 151.

When MUA 9 does not meet the minimum acceptable criteria for theapplication and it cannot be repaired 144, the MUA 9 may be re-rated andused in a different application 151. However, repeat AutoRULE scansshould minimize the number of unanticipated MUA 9 rejections. MUA 9deterioration should be tracked and preventive action 146 and 148 shouldmaximize the MUA 9 useful life.

FIG. 15 illustrates a typical RUL time sequence of a coiled tubing workcoil. The probability of failure 155F of similar coils can be divided inthree major segments marked by T1 and T2. Failures up to T1 are referredto as “infant mortality” while failures beyond T2 are primarily due towear (end of useful life). The baseline 155A shows the flaw spectrum ofa new coil. Since CO2 is predominant in the work area, it is anticipatedthat future AutoRULE scans would detect CO2 type corrosion (2-d) and thecoil is expected to follow RULE2 path of 155F. The probability of thisparticular coil “infant mortality” is lower because of the baseline155A. Preferably AutoRULE would include imperfection growth paths,morphology migration evaluation paths and root-cause identification. Forexample, the depth of a corrosion pit may increase and/or the corrosionpitting density may increase and/or a crack forming at the bottom of thepit would result in a critically flawed area (herein after referred toas “CFA”). CO2 type corrosion pitting appears in scan 155B exactly asexpected and it is predominant by scan 155C. Scans 155B and 155C showfeatures morphology migration. Because the work coil is undergoingbending in the plastic region (plastic deformation), the pits act asstress concentrators increasing the cyclic fatigue built-up rapidly. Themorphology shift toward fatigue cracking (2-D) is shown in 155D alongwith significant growth. The work coil shown in 155D has reached T2 in155F and it is no longer fit for service due to the imperfectionseverity (2-d). The only feasible remediation option is to remove thecoil from service work and re-rate it 148 as a production string wherethe coil will no longer be subjected to plastic deformation cycles.However, since the coil is under continuous in-service monitoring, thecoil was subjected to a few extra cycles, shown in 155E, when cracks(2-D) appeared, probably at the bottom of the CO2 corrosion pits (2-d).Cracks, a late fatigue life manifestation shown in 155E, grow rapidlythe coil would break within the next 3 cycles.

AutoRULE would preferably utilize a number of FFS and RULE paths. Forexample, when computer 20 monitors, logs and evaluates the overalldrilling performance, the RULE paths may be selected. The impact of thedrilling may be established by measuring the power consumption of thedrilling process, the string weight, weight on bit, applied torque,penetration rate and other related parameters. Such information, anindication of the strata and the efficiency of the drilling process, maydictate that a different FFS and RULE path and/or constraints should beutilized to further evaluate the MUA 9 RUL including imperfections 140.Furthermore, changes in the strata and/or in the efficiency of thedrilling process may indicate conditions that primarily induceimperfection morphology migration, not just growth, thus AutoRULE shouldalso include the anticipated deterioration mechanism acting on theimperfections.

Feature Duration

As mentioned earlier, it should be understood that the one to onecorrespondence of simple imperfections to the STYLWAN Flaw Spectrumoccasionally applies to machined (man-made) imperfections and not to thecomplex form imperfections typically found in nature. Therefore, theSTYLWAN Flaw Spectrum elements must be viewed as an entityidentification signature, just like DNA, but not as a detailed chemicalanalysis. It would be erroneous for example to conclude that a weld ismade up form a pit, three gouges and a wall thickness increase, theresult of a chemical-analysis-like interpretation of the Flaw Spectrumdata. The correct Flaw Spectrum interpretation would recognize thesignature of a weld and therefore, the first AutoRULE task would be torecognize complex imperfections, such as welds.

It should be readily apparent that complex feature would havesignificant 3D dimensions, as opposed to a single crack for example, andtherefore their Flaw Spectrum would have a much longer time and/orlength duration. If the AutoRULE was allowed to interpret signalsinstantaneously, the AutoRULE would behave erroneously, in achemical-analysis-like fashion, where a weld would be reported as astring of pits, gouges, CFAS and wall thickness changes. For example,the feature shown in 155C is a corrosion band, not a large number ofcorrosion pits, and the root-cause of the corrosion band is identifiedas CO2. Therefore, preventive action 146 should focus at minimizing theimpact of the CO2 environment on the work coil. Similarly, 155E showsmultiple CFAs and borderline CFAs, not just pits and cracks. Therefore,interpreting 155C through 155E instantaneously may lead to erroneousconclusions and possible instability.

It is desirable therefore, that AutoRULE processing preferablyincorporates feature duration data and/or trigger along with the abilityto revisit prior data and/or decisions. It should be noted that any timedelay between the feature passing through the head 2 and an AutoRULEdecision would be insignificant and unnoticeable by the operator.Furthermore, it should be noted that feature duration refers tosufficient duration that would lead to a valid AutoRULE conclusion andnot necessarily for the duration of the entire feature.

For example, a coiled tubing taper (a wall thickness change) may be manythousands of feet long while a localized wall loss could be six incheslong. On the onset of such a feature, it would be advisable to examine agreater MUA 9 length, ten feet for example, before the AutoRULE makes adecision. At 180′/minute scanning speed, ten feet delay would amount toabout one third (⅓) of a second that would certainly go unnoticeable bythe operator. Furthermore, even the AutoRULE shortest utterance, like“taper” or “weld”, would take longer than one third (⅓) of a second.

Complex Features

Again, complex features may be included in the MUA 9 by design, such astapers, collars and welds, and therefore may be shown in the historicaldata records and/or may be anticipated; may reflect repairs and/oralterations that are not shown in the historical data records and may ormay not be anticipated, such as a repair weld and lastly, they mayreflect imperfections that were not encountered on previous AutoRULEscans. Once the complex features is recognized 140, AutoRULE processingwould then proceed with the evaluation tasks prescribed for theparticular complex features and its ramifications upon the AutoRULEprocessing.

As discussed earlier, AutoRULE may retain more than one identifier forredundancy, conflict resolution, and system stability. It should then beunderstood that the recognition of complex features may involve morethan one identifier. Furthermore, complex features are the most likelycause of AutoRULE instability and as a precaution therefore, AutoRULE,once it reaches a decision, may re-examine the same features underlonger duration. This re-examination diminishes the probability ofinstability and increases the AutoRULE certainty, especially ifdifferent identifiers are implemented for the re-examination.

Assessment of Welds

Welding is the joining of two material pieces by applying heat with orwithout the use of filler material. Rarely used cold welding isaccomplished by applying high pressure. Welding induces residualstresses that FFS and FEA typically assume to be uniform throughout thematerial thickness (uniform stain field). During multipass welding forexample, the same point undergoes multiple thermal cycles multiple timesand secondly, not all points undergo the same number of thermal cycles.Therefore, it would be erroneous to assume that the weld residualstresses are uniform throughout the material thickness. Theheat-affected zone (herein after referred to as “HAZ”) is the portion ofthe base material that did not melt during welding, but the welding heataltered its properties.

Welds are complex features that are very common, just like couplings.Often, material with welds is derated, such as coiled tubing with a buttweld. In addition, a different derating factor is used for factory buttwelds and field butt welds. AutoRULE cannot make that distinctionautomatically. However, AutoRULE may search the local or remote historyand/or alteration record and/or may inquire for an entry from theoperator 138 and/or an expert. In the absence of additional information,preferably AutoRULE would evaluate the weld as a complex feature,feature rating, and rate the material pessimistically, statutory rating.Preferably, AutoRULE would retain and report both ratings.

Fatigue Assessment

For centuries, practicing engineers recognized that subjecting metal tostress cycles resulted in fractures although the forces involved were afraction of the forces required for static failure. The term Fatigue wasintroduced in the 19^(th) century probably by J. V. Poncelet(1788-1867). Fatigue initiates at the crystal imperfections, commonlyknown as dislocations. Dislocations can be viewed as atomic levelmicrocracks that act as stress concentrators starting the slipmechanism. Fatigue is cumulative and with additional stress cycles,fatigue progresses to cracking as the microcracks grow and bridge, apoint where failure is rapid.

Even the most sophisticated prediction models lack most of the detailedinformation required for a valid prediction. For example, OCTG maycontain 10¹⁰ dislocations/in³ on the average and while deployed may besubjected to unanticipated significant loads. Even if all the loads andthe exact nature of each dislocation were precisely known, any type ofcalculation, such as FEA, would be prohibitive. Furthermore, the problemof fatigue cracks rapidly magnifies when the material is subjected tocyclic loading in corrosive environments.

The advantage of AutoRULE is the large number of repeated assessmentsand data that can be collected without interfering with the deploymentof the MUA 9 or the production rate. AutoRULE detects the actualcondition of the MUA 9 fatigue regardless of the underline causes.Fatigue build-up tests with the exemplary RDIS-10 revealed that fatigueup to ≈50% of the life cycle falls in the 2-Dα spectrum segment, between≈50% and ≈75% falls in the 2-Dβ spectrum segment and above ≈75% falls inthe 2-Dγ spectrum segment.

Most software failure prediction models are aimed at predicting thealpha failure location (herein after referred to as “(αFL)”); thelocation where the rate of fatigue build-up is the highest andtherefore, it is the location where the first failure is expected tooccur. RDIS-10 fatigue build-up tests revealed that multiple (aFL) canbe identified at the boundary transition between 2-Dα and 2-Dβ while thefailure location can be identified at about 65% of the life cycle whenpreventive action 143 becomes extremely important.

The most catastrophic form of failure is Early alpha failure (hereinafter referred to as “(EαFL)”) that is not predicted by any model butAutoRULE would easily detect 142 the rapid fatigue build-up. An (EaFL)most likely would be the result of MUI 1 that does not meet thespecifications or material that was damaged during transportation andhandling following the inspection.

Crack-Like Imperfection Assessment

In-service fatigue build-up typically initiates surface cracking. Cracksalso initiate at the bottom of other imperfections, such as pits, thatact as stress concentrator as shown in 155E. Modeling and predictingcrack growth is extremely imprecise, just like modeling fatigue. Again,AutoRULE scans, preferably after every use, would track the actual crackgrowth and propagation regardless of the underline causes. A measure ofthe energy released per crack surface area may be calculated from theAutoRULE data. Without additional loads and when crack growth reachesits limit, AutoRULE may calculate the residual stresses that contributedto the crack growth. Such data may supplement the historical data of allmaterials deployed in similar applications. Preferably, such databasewould reside in a central remote location in communication withAutoRULE. Significant remaining useful life of the MUA 9 may berecovered if the crack 7A in FIG. 3A is morphed 145 into a 3-D typeimperfection 7B (much lower stress concentration) as shown in FIG. 3B,but only if the neighborhood of crack 7A is free from otherimperfections. Therefore, effective preventive action 146 is essential.

Crack growth and propagation is highly sensitive to changes in theapplication or the environment. As carried out, RULE assessmenttypically utilizes theoretical data and/or experimental data that wereobtained in a laboratory under carefully controlled conditions. Suchdata are not always appropriate for field use. AutoRULE data on theother hand, reflect actual field conditions and material performance andtherefore capture the actual material RULE for the particularapplication and/or environment.

Pitting Assessment

For isolated pits, 2-d through 3-d assessment would examine theproximity of other imperfections to the pit that may form a CFA underthe regiment of anticipated loads as shown in 155E. Once the material isdetermined to be free of CFAs, discussed further below, AutoRULE wouldthen establish severity of the pit.

For corrosion bands, 2-d through 3-d assessment would first establishthe boundaries of the corrosion region (imperfection duration and areacoverage). Then AutoRULE would determine if the corrosion region damageis still acceptable 142 and that the region is not growing at anunacceptable rate by utilizing previous RULE records 137, such as 155Cand 155D. AutoRULE would then attempt to identify the nature of thecorrosion mechanism. Different mechanisms result in different types ofcorrosion pitting such as narrow base cylindrical pits all the way tobroad based conical pits and FDDim may be used as a corrosion mechanismguide and thus a guide to the root-cause identification and the properremediation 145, 146.

For example, when CO2 type pits appear on MUI 1 that was free of CO2pits in previous AutoRULE scans, it is reasonable to conclude that CO2backflooding has reached the particular well site. This change in theoperating environment significantly impacts the remaining MUA 9 lifewhich can be recalculated and extended by the proper application ofinhibitors or by simply rearranging the tubing in a well. Furthermore,early detection of the CO2 presence may redefine the next preventivemaintenance service interval. This unique and novel feature of theAutoRULE is not available with the sporadic inspections which morelikely would take place after the MUA 9 failed prematurely because ofthe accelerated CO2 corrosion.

This example also demonstrates another AutoRULE strength versus RULE and1D-NDI as carried out. Lets assume that the production tubing was in awell for 4 years prior to CO2 reaching the well site and that a tubingfailure occurs 1 year after CO2 reached the well site. RULE assessmentand 1D-NDI would then reasonably conclude that the tubing time tofailure in the particular well is 5 years (tube useful life), when infact it is only 1 year. Due to costs involved, it is unlikely that1D-NDI would be deployed during a workover and even if 1D-NDI isdeployed, 1D-NDI could not detect the change in the environment. By thetime the owner figures out the new oilfield realities, followingmultiple tubing failures, a vast number of production tubing strings mayneed replacing while an AutoRULE assessment would alert the owner aboutthe subterranean environment changes and recommend a preventive action143 early on, thus extending the life of multiple production strings. Itshould then be understood that AutoRULE frequent utilization, preferablyon every workover, could have significant ramifications for the entireoperation, not just the particular well.

Critically Flawed Area Assessment

CFA is a complex encounter where imperfections in proximity aredynamically linked under loading, such as a corrosion pit with a crackat the bottom (similar to the CFA of FIG. 3C) or imperfections inproximity and orientation as to experience increased stressconcentration. The detection of such a CFA early on may not necessarilymean rejection of MUA 9 as simple precautions 146, such as minimizingthe cycling of the particular MUA 9 location, may be sufficient and itmay extend the use of the MUA 9. In addition, with a AutoRULEcontinuously monitoring the CFA, the full useful life of the MUA 9 maybe used despite the presents of the CFA as long as the CFA growth and/ormorphology migration remain within acceptable limits as shown in 155Dand 155E.

It should also be noted that the AutoRULE processing is diametricallyopposing the 1D-NDI processing whereby a single uncorrected signal isused to pass or send the material for verification. Since theuncorrected signal of a small crack at the bottom of a pit does notsignificantly alter the pit signal, 1D-NDI would pass the material withthe CFA as long as the pit signal itself does exceed the presetmagnitude limit. It is also important to observe that corrosion pitsoccur at the surface of materials and in materials that endure dynamicloading, such as coiled tubing, drill pipe and marine drilling risers,the pits, the welds and other imperfections act as stress concentrators.Cracking would then initiate at the stress concentrators, like thebottom of the pits or the heat affected zone of welds, but such CFAswould go unnoticed by the TOFD of U.S. Pat. No. 6,904,818 because theCFAs would fall within the TOFD near-surface and far-surface detectiondead-zones.

3-d and 3-D Assessment

Imperfections like grooves and gauges along with material hardnesschanges typically fall into this segment of the flaw spectrum. Groovestypically arise from erosion or corrosion while gauges are mostly theresult of mechanical damage. Dents and deformations, discussed furtherbelow, often include gauges, scratches and notches. 2-D and 2-dremediation action, as shown in FIG. 3B, also results in imperfectionsthat typically fall into this segment.

When an excavator accidentally hits a pipeline, it will dent it, thus itwould plastically change the pipeline material. Interaction with theenvironment may change the material properties and it may change theplastically deformed dent region at a different rate than the undamagedpipeline material. During pumping, the pipeline pressure varies at afrequency that may lead to a crack in the deformed area.

Hardness estimates the strength of the material and its resistance towear. Hardness changes, such as a hard spot, effect the remaining usefullife of the MUA 9 differently from wall thickness related features. Forexample, in material enduring cycles of tension and compression thevicinity of the hard spot would experience significantly increasedloading and increased fatigue built-up, a potential (EaFL).

Wall Thickness Assessment

Wall thickness assessment may utilize the wall thickness profile(minimum, nominal, design, maximum), the wall thickness variationprofile, the cross-sectional area profile and the average wall thicknessprofile, preferably all covering one-hundred percent (100%) of the MUI 1continuously.

As mentioned earlier, wall thickness changes, by design or otherwise,may be used to alter the AutoRULE processing. For example, a pipecoupling would appear as a significant wall thickness increase and maybe used to invoke the AutoRULE coupling inspection.

3-G Deformation Assessment

Irregularities in the MUA 9 geometry, such as balooning, dents,eccentricity, neck-down, ovality, misaligned welds and straightnesstypically fall into this category. Deformations may originate inmanufacturing, such as eccentricity; may be the result of a repair, suchas a misaligned weld and lastly deformations may be induced duringdeployment, such as dents, ovality and balooning. Dents and gouges aretypically the results of mechanical action, such as an excavator hittinga pipeline. The fact that material is not straight, such as a bend drillpipe joint, is an indication that the material's yield strength wasexceeded during deployment. A bend drill pipe joint would most likevibrate, increase the fatigue build-up and increase the wear on both thejoint and any casing is deployed through.

Coiled tubing endures plastic deformation and it is an example of useinduced deformation. When tubing bends, the fibers at the major axishave to travel further (extend) than the fibers on the minor axis(compress). This involves an amount of stored energy. In order tominimize the amount of stored energy, the tube swells sideways (neutralaxis) and assumes an oval cross-section (ovality). By doing so, itminimizes the major axis fiber extension and the minor axis fibercompression. AutoRULE uses 3-G information directly and/or as aprocessing selection guide.

Material Deployment Loads

During deployment, materials may experience bending, buckling,compression, cyclic loading, deflection, deformation, dynamic linking,dynamic loading, elastic deformation, eccentric loading, featurepropagation, impulse, loading, misallignement, moments, offset,oscillation, plastic deformation, propagation, shear, static loading,strain, stress, tension, thermal loading, torsion, twisting, vibration,and/or a combination thereof.

As it is well known, MUA 9 features behave differently under differentloading and therefore AutoRULE would have to evaluate the features itencounters under all the anticipated types of loading 140 and anycombination thereof. For example, drill pipe in a dog leg would also besubjected to bending in addition to torsion and loading. Furthermore,re-rating 148 MUA 9 early on may extend the MUA 9 useful life.

AutoRULE Feasibility

The overall system must be feasible not only from the classificationstandpoint but also from the realization standpoint. In addition to theclassification and minimum error, the system constrains also include,but are not limited to, cost, packaging, portability, reliability, andease of use; all of which should be addressed in each step of thedesign. The system design preferably must assign initial resources toeach level and should attempt to minimize or even eliminate resourceswhose overall contribution is negligible. This can be accomplished byconverting certain features to bias and evaluating the resulting error.

Computer 20 preferably recognizes the feature by comparing the finalarray of identifiers 135, 136, 139 with a stored features templatedatabase. Once a feature is recognized, computer 20 may verify thecorrectness of the recognition by further evaluating intermediateidentifiers.

AutoRULE Instability and Conflict Resolution

Occasionally, the feature recognition becomes unstable with the finalarray of identifiers toggling between two solutions on each iteration.For example, during the inspection of used production tubing, therecognition may bounce back and forth between a large crack or a smallpit. Resolution of such instability may be achieved by varying thefeature duration length, utilizing intermediate identifiers, byutilizing the previous recognition value, or by always accepting theworst conclusion (typically referred to as pessimistic classification).However, AutoRULE instability may also be the outcome of improperbackwards chaining or even faulty constrains. Slight increase in thecoefficients of the backwards chained features may produce an outputoscillation thus rapidly locating the problem feature and/orcoefficients.

A conflict arises when the final array of identifiers points into two ormore different MUA 9 conditions with equal probability. Again,resolution of such conflict may be achieved by utilizing intermediateidentifiers, by utilizing the previous recognition value or by alwaysaccepting the worst conclusion. However, a definite solution may beobtained by eliminating features that the conclusions have invalidatedand by reprocessing the signals under the new rules.

The AutoRULE is preferably designed to reason under certainty. However,it should also be capable of reasoning under uncertainty. For example,during the assessment of used production tubing of a gas well, rodwearis detected. Since there are no sucker rods in the gas well, theconclusion is that this is either used tubing that was previouslyutilized in a well with sucker rod or there is a failure in theAutoRULE. The AutoRULE could query the operator 138 about the history ofthe tubing and specifically if it was new or used when initiallyinstalled in the well. The answer may be difficult to obtain, thereforea 50-50 chance should be accepted. A bias value may then be altered andthe signal may be reprocessed under the new rules.

Alternate coefficients may be stored for use when certain failures aredetected. For example, the wellhead pressure transmitter may fail. Upondetection of the failure, the alternate set of coefficients should beloaded for further use. It should be understood that even a simple biasmay substitute for the failed transmitter.

RULE Calibration Sample

FIG. 16A illustrates a calibration sample with four features for usewith AutoRULE to evaluate the AutoRULE feature identificationcapabilities and tune its parameters for the specific RULE needs of theparticular material/application. Imperfection 156A is a crack-likeimperfection, 156B is a pit-like imperfection, 156C is a gouge-likeimperfection and 156D is a wall thickness feature. It should beunderstood that the calibration sample may contain multiple featuresand/or multiple examples of similar features with varying geometries. Itshould further be understood that features may be located on the OD orthe ID of the material or both the OD and ID.

FIG. 16B illustrates a calibration sample with two coexistingimperfections for use with AutoRULE to evaluate the AutoRULE coexistingimperfection separation and identification capabilities and tune itsparameters for the specific RULE needs of the particularmaterial/application. Imperfection 157 is a crack-like imperfectioncoexisting with a pit-like imperfection. It should be understood thatthe calibration sample may contain multiple coexisting features and/ormultiple examples of similar coexisting features with varyinggeometries. It should further be understood that coexisting features maybe located on the OD or the ID of the material or both the OD and ID.

Not shown are calibration samples with additional features, such ascouplings, welds, deformation and the like, that may be utilized, asdictated by the particular material and/or application. Therefore itwould be appreciated that standard threaded connections and/or weldedsections, and the like, may be used for calibration.

Remediation

As discussed earlier and referring back to FIG. 3, 1D-NDI will typicallymiss imperfection 7B as it will also miss FIG. 16D imperfection 159.Furthermore, 1D-NDI recommended remediation for imperfection 7A does notaccount for the vicinity of imperfection 7A. For example, ifimperfection 7B was located on the ID below imperfection 7A, the 1D-NDIremediation action for 7A would instead result in a differentlydefective material that is acceptable by 1D-NDI but rejectable byAutoRULE.

AutoRULE must calculate the optimal remediation profile along with theremediation feasibility. For example, it will be straight forward forAutoRULE to calculate the optimal remediation profile 7B for externalimperfections 7A or 158 and such remediation is feasible. It will be byfar more complex to calculate the optimal remediation profile forexternal imperfections 159. AutoRULE will first calculate the optimalremediation profile for each one of the imperfections making up 159.AutoRULE would then examine the neighborhood for each morphology shiftedimperfection making up 159. This may result in a remediation profilethat is no longer optimal and therefore, AutoRULE will calculate anoptimal remediation profile combining two or more of the morphologyshifted imperfections making up 159. This iterative process may continueuntil an optimal remediation profile for 159 is calculated or untilAutoRULE decides that no remediation is feasible. For example, repeatremediation iterations for imperfection 159 may lead to an optimalremediation profile resulting in a groove around the circumference ofMUA 9. This groove may render MUA 9 unfit for continuing service.AutoRULE would then have to calculate an optimal remediation profile forthe groove that material failure illustrated in FIGS. 2A through 2D. Theflagged material is then send for verification 161.

Material 165 may then contain an assortment of imperfections, somebecause of the 1D-NDI “standardization” practice, like an 75% drilledhole; some because of missed imperfections, due to “sensor liftoff” or“detection dead-zones”, and some because of errors and/or omissionseither by the inspector or by the verification crew. Material 165 isthen exposed to potential accidental damage during transportation andhandling to the site of use 169. During deployment, the material mayendure unexpected loads or suffer unexpected damage 167, but thecondition of the material 168 will not be ascertained again until thenext inspection cycle or after a failure.

Because of its implementation and the intrusion NDI imposes, typicalinspections have been expensive and are thus performed at rare intervalsor not performed at all. For example, NDI costs of OCTG can be as highas 30% of the material replacement cost.

In the rare occasion that an analysis follows the NDI, the inspectionresults 163 are send for evaluation while the material is shipped to theuse site 169. The evaluation process 164 may incorporate design andhistorical data 162 and eventual approval for the material use may begranted well after the material has reached the use site 169. Because ofthe evaluation process 163 inherent delay and cost, along with othereconomic pressures, the material 166 is typically put to use immediatelyupon arrival at the use site 169 and the evaluation process is reducedto a search for the failure mechanism of the rejected material.

Pipelines on the other hand, are typically inspected by internalinspection units commonly known as pipeline pigs or pigs. Following thescan, the inspection data is sent for evaluation 163 while the pipelineis put back into service. It is obvious that areas of concern cannot beidentified until trained inspectors examine the inspection data, aprocess that typically takes weeks if not months. It is not uncommon fora verification report to be generated months after the inspectionidentifying hundreds of areas of concern requiring manual verification.Manual verification for pipelines involves crews with heavy equipmentthat would travel to the designated areas, dig up the pipeline andperform manual inspections to evaluate the nature and extent of theimperfections that gave rise to the pig signals. The verificationresults would then be sent for evaluation 163 and approval 164, monthsafter the pipeline was put back into service following the inspection.In the meanwhile, a pipeline leak may develop in one of the areasdesignated for verification or even in an area that was not flagged bythe pig. Such detection failure may arise from the 1D-NDI limitationsthat result in specialized inspection pigs such a pitting inspectionpigs, crack inspection pigs etc.

On the other hand, AutoRULE must examine and evaluate, as close aspossible, 100% of the MUA 9 for 100% of pertinent features and declarethe MUA 9 fit for continuing service only after the impact of all thedetected features upon the MUA 9 have been evaluated and estimate itsRUL; diametrically opposing the 1D-NDI methodology. It is well knownthat the presence of any imperfection alters the expected (designed)life of the MUA 9 and thus impacts its RUL. Thus, it should beappreciated that the deployment of the AutoRULE would increase theoverall safety and reliability as it would lead to MUA 9repair/replacement prior to a catastrophic failure as well as it willreduce and/or eliminate its premature replacement due to concerns whenthe conventional inspection periods are spaced far apart and/or when theconventional inspection provides an insignificant inspection coverage.

FIG. 18 illustrates a typical AutoRULE process. Preferably, an AutoRULEbaseline 170 is obtained prior to the deployment of the MUA 9. It shouldbe understood that any subsequent onsite AutoRULE scans 171 become thebaseline, historical data 162, for the next scan, therefore, the firstbaseline may also be obtained during the first AutoRULE scan 171 at thedeployment site 169. Onsite AutoRULE scans 171 would assure thatmaterial 168 is still fit for service “as-is” including anytransportation and/or handling damage 166 or any use-induced damage 167.A remote expert 172 may review the AutoRULE data, may convert and runthe AutoRULE data with finite element analysis engine and/or may alterthe AutoRULE processing.

FIG. 19A illustrates a typical AutoRULE operator readout 180 preferablyfor use to acquire laboratory and/or field data for the developmentand/or verification of FFS and RUL. It should be understood that theAutoRULE operator readout 180 is provided in addition to the speech andsound interface. It should be further understood that this particularAutoRULE implementation is for illustration purposes only and should notbe interpreted as limiting in any fashion. This particular AutoRULEoperator readout 180 comprises of the three-dimensional finite elementinspection (herein after referred to as “3D-FEI”) readout 181, theAutoNDI readout 182 and the AutoFFS readout 183 and the AutoRULE readout184. This particular AutoRULE assigns a fitness number to the MUA 9between 0 and 100. Fit for service material is assigned a number between50 and 100 (green). Material that is fit for service under continuousmonitoring is assigned a number between 25 and 49 (yellow). Unfit forservice material is

Preferably, AutoRULE would be capable of utilizing multiple paths of MUA9 assessment. In this particular AutoRULE implementation, the operatormay evaluate MUA 9 under three different FFS paths 197 and under threedifferent RUL paths 198. It should be understood that reprocessing paths197 and 198 may not necessarily reflect the current MUA 9 deployment butthe next or a future MUA 9 deployment. For example, the drill pipeillustrated in FIG. 19B may be evaluated using the next well (differentstrata) FFS and RUL and/or it may be segregated for further deploymentin different wells to maximize the RUL of each joint in the string. Itshould be further understood that reprocessing of data through paths 197and 198 is rapid, as the data preferably would be stored in a localstorage device and/or in a storage device affixed onto the MUA 9.Storing data in a memory affixed onto the MUA 9 provides significantadvantages versus searching a database for such data.

All of the AutoRULE data are available for examination by the operatorand the remote expert 172. Similarly, the internal memory of an AutoRULEpipeline pig can be examined rapidly in minutes instead of weeks ormonths. The pipeline can be put back to service with confidence or theremediation effort can start immediately with the areas that weredetermined to be unfit for service. In addition, FEA can also beutilized to augment and/or verify the AutoRULE data as an additionalsafety measure.

Exporting AutoRULE Data to an FEA Engine

With the advent of desktop computers and design/drafting software, FEAis in wide use today. It is typically utilized during the design phaseto analyze as-designed structures. It should be understood that FEAengines operate on physical structures (something) under static orAutoRULE conversion would translate the AutoRULE data to a drawing foruse by a commercially available drafting program, such as AutoCAD. Othercommercially available programs would then export the drawing data to anFEA engine.

Having a physical description of the MUA 9 (structure) alone isinsufficient information for FEA, as the loads involved are alsorequired. Typically, the MUA 9 is analyzed under a regiment ofanticipated loads that reflect the opinion of experts. A unique featureof AutoRULE is the data acquisition system 35 and sensors 36 and 37. Asdiscussed earlier, computer 20 may also monitor, through the dataacquisition system 35, parameters that are related to the assessment orutilization of the MUA 9 and/or parameters to facilitate RULE and/orremaining useful life estimation. Such parameters may include, but notbe limited to, the MUA 9 pump pressure, external pressure, such as thewellhead pressure, temperature, flow rate, tension, weight, loaddistribution, fluid volume and pump rate and the like. Preferably, theseparameters are measured or acquired through sensors and/or transducersmounted throughout the MUA 9 deployment area 169, such as a rig or onthe MUA 9, such as a vibration monitor. For ease of understanding, thesevarious sensors and transducers are designated with the numeral 37.Therefore, and in addition to the physical description of the MUA 9,AutoRULE would also acquire and export information regarding the actualdeployment condition parameters 173 and the actual loads 174, includingactual and the unanticipated loads the MUA 9 endures resulting in aas-is and as-used FEA.

It should be understood that not all AutoRULE features can be convertedto a geometrical structure for use by an FEA engine, such as fatigue.Instead, such features affect the remaining useful life of the material.It should be further understood that setting the FEA boundaries andaccepting, interpreting and understanding the overall FEA process dataand results is beyond the anticipate capabilities of the onsite AutoRULEoperator, and therefore, this task is assigned to a remote expert 172 orgroup of experts.

It may be seen from the preceding description that a novel AutonomousRemaining Useful Life Estimation system and control has been providedthat is simple and straightforward to implement. Although specificexamples may have been described and disclosed, the invention of theinstant application is considered to comprise and is intended tocomprise any equivalent structure and may be constructed in manydifferent ways to function and operate in the general manner asexplained hereinbefore. Accordingly, it is noted that the embodimentsdescribed herein in detail for exemplary purposes are of course subjectto many different variations in structure, design, application andmethodology. Because many varying and different embodiments may be madewithin the scope of the inventive concept(s) herein taught, and becausemany modifications may be made in the embodiment herein detailed inaccordance with the descriptive requirements of the law, it is to beunderstood that the details herein are to be interpreted as illustrativeand not in a limiting sense.

FIG. 16C illustrates a range of 1D-NDI recommended calibration/referenceimperfections. It is of interest to notice the machining precisionspecified for the reference imperfections. As a general rule, thetighter the machining tolerances for the reference imperfection, theleast likely the imperfection would be encountered in nature.Furthermore, MUI with any diameter pit, 1/16″ or otherwise, should berejected for further use way before the pit becomes a hole (100%penetration), regardless of the machining tolerances. Again, as shown inFIGS. 2A and 2B, 1D-NDI would easily mislead someone to believe that a5% notch or a 100% pit (a hole) are appropriate calibration/referencestandards and the tight machining tolerances add a false sense ofconfidence in 1D-NDI.

FIG. 16D illustrates yet another situation that 1D-NDI would mislead theinspector. Imperfection 159 consists of a number of imperfections 158.The highest signal selector 10 of 1D-NDI would propagate to the readout5 the signal of only one of the imperfections 159 resulting in anidentical inspection trace for imperfections 158 and 159. Strength ofmaterial knowledge (and common sense) teaches that the MUA 9 will breakat 159 when subjected to loads such as bending, torsion, cyclic loadingetc. If imperfection 158 did not cross the 1D-NDI threshold level, then159 will not cross the 1D-NDI threshold level either due to the 1D-NDIsignal processing. Even if imperfections 158 and 159 did cross the1D-NDI threshold level, it is unlikely that 159 would be recognized as aCFA by the verification crew and it is highly unlikely if imperfections158 and 159 were located in the ID of MUA 9. On the other hand, AutoRULEwould evaluate each 159 imperfection on its own and apply neighborhoodcorrection factors, thus distinguishing imperfection 159 from 158.

would result in a fit for continuing service MUI or re-rated 148 MUI.Therefore, AutoRULE optimal remediation profile calculations willcontinue until at least two consecutive unfit for service calculationshave been performed.

NDI and AutoRULE Utilization

FIG. 17 illustrates a typical NDI process. As practiced today, NDIdictates termination of the material utilization altogether in order toaccommodate the inspection process, which, is typically carried out byshipping the material to an inspection facility. The cost of inspectionis therefore increased by the transportation cost and the materialdowntime. In addition, shipping and handling the material, especiallyafter the inspection 165, may induce damage to the material that couldresult in an unanticipated early catastrophic failure.

During inspection 160, the MUI 1 is examined for indications (flags),such as “ . . . regions of abnormal magnetic reluctance (or echo, orphase shift etc)”, that exceed a preset threshold level. A typical1D-NDI equipment “standardization” practice sets the threshold level byscanning a “reference standard” as shown in FIG. 16C. Again, referringback to FIGS. 2A and 2B, it is easy to see how someone may be mislead tobelieve that “standardization of the 1D-NDI equipment” would somehow beequally accomplished by “referencing” a 1D-NDI unit on a “through-walldrilled hole”, a 3-d imperfection with 0% remaining wall thickness, or a“5% OD notch”, a 2-D imperfection with 95% remaining wall thickness.Therefore, the 1D-NDI equipment is “standardized” to flag imperfectionswith wall loss anywhere between 5% up to 100% depending on the geometryof the imperfection; the 1D-NDI practice that led to the dassigned anumber between 0 and 24 (red). This particular AutoRULE also assigns aRUL number to the MUA 9 between 0 and 100.

It should be understood that while acquiring data for the developmentand/or verification of an FFS and a RUL, the MUA 9 would preferably beunder continuous monitoring by the 3D-FEI 181 and AutoNDI 182 andtherefore minimizing the risk while extending the data collection range,as described in FIG. 15. Typically, the exemplary RDIS-10 or a similardevice would provide the 3D-FEI traces while AutoNDI is fully describedin U.S. Pat. No. 7,155,369.

FIG. 19B illustrates a typical AutoRULE operator readout 190 configuredfor drill pipe (MUA 9). AutoRULE configuration menu is accessed throughthe “Profile” button or by speaking the word “Profile”. The 3D-FEIreadout shows a drill tool joint 191A, a complex feature. As discussedearlier, if the AutoRULE was allowed to interpret the tool joint 191Asignals instantaneously, AutoRULE would behave erroneously, in achemical-analysis-like fashion, and will report that the tool joint 191Ais made up by wall thickness increase and a number of assortedimperfections. It should be understood that 1D-NDI assigns this taskentirely to the inspector and relies exclusively on the inspectorsabilities. Instead, AutoRULE feature recognition processing, identifiedthe tool joint 191A (and 191B), altered the processing path 192A andcalculated the FFS 193 and RULE 194 of the tool joint 191A using adifferent assessment path than the drill pipe body wall path. Thisparticular AutoRULE assessment declared both the drill pipe body walland the tool joint fit for service (green—above mid point) with RULranging from 96 to 100%. Bargraph 195 shows the joint RUL and 196 showsthe drill string RUL. Similar bargraph shows the joint FFS the drillstring FFS.

dynamic loading, not features alone, as features alone do not exist innature. For example, a corrosion pit does not exist on its own. Acorrosion pit exists as a feature on a physical structure, such apipeline. Typically, the geometry of a feature is expressed aspercentage of the physical structure geometry. For example, a 10% pitdepth is a meaningless expression without knowing the wall thickness ofthe material, the physical structure. Therefore, a 10% pit on a 0.095″wall thickness coiled tubing has a depth of 0.0095″ and on a 1.000″ wallthickness riser auxiliary line has a depth of 0.100″. AutoRULE (andNDI), typically relay to the operator information regarding the severity(presence) of a feature (imperfection, defect) in a format such as shownin FIG. 2A, FIG. 2C and FIG. 19B.

However, FEA Engines cannot operate on the data, such as shown in FIG.2C and FIG. 19B. FEA Engines can only operate on a structure, such asshown in FIG. 3A through FIG. 3C, and evaluate the localized stresses ofthe structure under specific loading, as shown in FIG. 3D. It should benoted that 1D-NDI data are insufficient for FEA as 1D-NDI processingeliminates most of the material features information, as discussedearlier.

On occasion, it is desirable to analyze the as-is material with FEA toobtain, for example, deflection, strains, stresses, natural frequenciesand similar data. Converting manually the AutoRULE signals to astructure requires a number of multidiscipline experts and it is timeconsuming. Therefore, it is desirable to provide a program that canconvert automatically the AutoRULE material features to a geometricalstructure for use by a commercially available FEA engine. It should beunderstood that such conversion would depend on the particular AutoRULEcapabilities and the particular FEA engine geometry file specifications.A more general

1.-49. (canceled)
 50. A method to evaluate material comprising:detecting physical phenomena in an environment in which a material underevaluation is utilized; scanning said material under evaluation todetect material features; programming a computer to utilize digitalsignals produced in response to said detecting and said scanning tocalculate a remaining useful life of said material under evaluation. 51.A method to evaluate material comprising: programming a computer with aplurality of remaining useful life paths for evaluating a material underevaluation; scanning said material under evaluation to detect at leastone of a plurality of material features; and selecting from saidplurality of remaining useful life paths to determine a remaining usefullife of said material under evaluation.
 52. A method to evaluatematerial comprising: repeatedly scanning a material under evaluationover time to detect new material features and monitor previouslydetected material features; programming a computer to analyze dataproduced during said step of repeatedly scanning to determine at leastone degradation mechanism from a plurality of possible degradationmechanisms affecting said material under evaluation from a plurality.53. The method of claim 52, further comprising, programming saidcomputer to recommend a preventative action to inhibit said at least onedegradation mechanism.
 54. A method to calibrate a remaining useful lifeevaluation system comprising: providing at least one material sample,with at least one feature impacting a material remaining useful life andwhereby a remaining useful life evaluation outcome of said materialsample is known; evaluating said material sample with said remaininguseful life evaluation system; adjusting said remaining useful lifeevaluation system, whereby an evaluation outcome of said material samplematches a known remaining useful life of said material sample.
 55. Themethod of claim 54, whereby said material sample comprises a pluralityof features impacting the material remaining useful life and whereby acorresponding remaining useful life evaluation outcome of said materialsample is known.
 56. The method of claim 54, whereby said materialsample feature comprises two or more coexisting features impacting thematerial remaining useful life and whereby a corresponding remaininguseful life evaluation outcome of said material sample is known. 57.-59.(canceled)